The British left India in 1947, but much of the English phraseology still used in India is possibly over 100 years old, if not more. While there is nothing wrong with that — Americans also use a lot of words left by the British in 1773 and abandoned later in the UK — you need to be aware when you are using outdated language, particularly when writing on a paid basis for a Western audience. How you speak or write in India is up to you.
Advocate
An advocate in the West is an impartial product champion who will say good things about a product without any prompting. In the US, the legally qualified professional is called a Lawyer and in British-influenced countries, this is a Solicitor and/or Barrister.
Alphabet
The Alphabet is the set of letters from A through Z. It is not a synonym for letters.
Appear
Indians appear for an exam; New Zealanders sit an exam.
Back
An Indian will say, “I went to London five years back“; others will say, “I went to London five years ago.”
Bifurcate
Indian roads can be bifurcated (split into two roads). Elsewhere, they fork.
Community
An Indian might be thinking of his sub-caste when he refers to his community.
Cousin Brother/Sister
In the West, they are simply cousins. You have to determine their gender using all available clues.
Drawing Room
You’d be hard pressed to find a drawing room in the UK today, but you’ll find a lot of living rooms. Australians watch TV or entertain guests in their lounge rooms, while Kiwis do likewise in their lounge.
Encounter
Sometime after 1980, Bombay policemen stopped having shootouts with criminals; they had encounters (which was also a convenient excuse for disposing of people).
Eve Teasing
In the West, we call it sexual harrassment, plain and simple. Call a spade a spade. Shame on the Indian news media for still using this gross understatement.
Executive
In India, a junior staff member is an Executive; in the West, a very senior manager is an Executive.
Expire
Indians expire; everyone else dies.
Flyover
For many years, Bombayites were proud of their first flyover at Kemp’s Corner and all the others that followed. You might get a blank look in the West if you talk about flyovers, as the freeways, tollways, turnpikes, or motorways have lots of underpasses, overpasses, on-ramps, off-ramps, etc within a short distance. They don’t have culverts, either. A road is a road; it goes up, it goes down; it goes above other roads; it goes under roads. Get over it. 
Godown
In India and in Singapore, you store goods in a godown, but the rest of the world does so in a warehouse.
Hotel
Be clear that you are not referring to a cafe or a restaurant. This is indeed a confusing word even in the West. In Australia, a hotel can be a large pub that also offers accommodation, or it can be a multi-storey building where you can rent a bedroom and drink in its bar.
House Full
Indian movie theatres might put up a House Full sign; in Australia, the notice will read Full House.
Issue
A court case in India might refer to the issues of a couple. Elsewhere, a similar case would refer to children.
Kindly
When you say, “Kindly (do something)”, it might be taken as sarcasm, as in “Kindly go away”. Say, “Please (do something)”.
Lakh
Whether you spell it as lakh or lac (yikes), a Western reader won’t understand it. If you place a comma after the fifth digit (1,00,000), you’ll confuse them. Just talk in millions and place a zero after the sixth digit.
Miscreant
In the West, a miscreant is referred to as a troublemaker, vandal, or criminal.
Mofussil
In Chennai they not only use the word mofussil to refer to the countryside – the interior – the outback – up country, but they built the Chennai Mofussil Bus Terminus.
Mugging
Indian (or British public school) students say they are mugging for an exam; elsewhere, rote learning (or learning by rote) is frowned upon.
Native Place
Indians come from somewhere, which they refer to as their native place, although sometimes this is where their ancestors came from. In the West, you move around so much that nobody really cares where you or your ancestors were born. At best, that was your home town.
Non-Vegetarian
In the West, people who eat meat are just people; others who don’t eat meat are vegetarians or vegans (Indians who are vegetarians should ask for the local definition of either term, as it is not consistent. Some Western vegetarians eat fish or eggs).
Number
Asking for “10 numbers” of something is incorrect English — it is not even Indian English. Just ask for 10 of something — I think we can figure out that 10 is a number.
Office
Westerners go to work. They don’t all work in an office (although many/most Indians who speak English probably do).
Peg
Whether you have a peg of whisky or a shot of whisky, it tastes just as good.
Placement Agency
In the West, you might find a placement agency, but there are many more recruitment agencies.
Residence
Indians live at their residence; others live at home.
Revert
When Indians reply to a letter or telephone call, they revert. In the West people reply, or get back to the caller. To revert means to return to the original state or condition.
Sharp
Indians rarely manage to turn up on time for an appointment (usually owing to heavy traffic), so they need to add this word, as in “6 pm sharp”. Elsewhere, “6 pm” means “6 pm” and not a second sooner or later.
Sofa Cum Bed
You might get a nervous giggle if you inserted cum in sofa bed in Australia.
Tubelight
Don’t look for a tubelight in Australia. Ask for a fluorescent tube.