Here are some phrases I've heard (I've tried not to repeat what the others said!):
'Roundtana' for roundabouts (this was in Chennai).
"Light chali gayi"- There's been a power cut/failure.
We morph 'stand at ease' into a rapidly fired 'standatees'!
'Cousin brother/sister'. Just cousin is fine!
'Is this a classroom or a fish-market?' I suppose every Indian student has heard this from a teacher, at least once in a lifetime.
'Bulb', 'popat' or 'chop' for foot-in-mouth/slightly ironic situations. You said you would pass with flying colours and you didn't, now that's what I call a chop/popat/bulb.The chop/popat/bulb you get when your best friend doesn't consider you to be
their best friend.
'Scale' instead of ruler, 'rounder' instead of compass, 'buckle' instead of hair clip (thanks, Gujaratis).
The 'i' epenthesis from Hindi and the 'y' and 'u' epenthesis from South Indian languages. Mujhe isscale chahiye (I want a ruler). Why do you have to borrow yeverything from others? You can't bring your own thingsu?
The way we pronounce 'yeah' (yaa), and appending that to every sentence that slips out of our mouths. Take care yaa. Yaa, I will.
'Classwork'- the equivalent of homework; it's the work you do in class.
I'll add more if/when they occur to me!