Indianisms, from useful to hilarious

Prepone - Like postpone, but to have a meeting earlier rather than later.
Upgradation - To upgrade, obviously.
Do the needful and the same - "Here's the form.  Please do the needful at your earliest convenience and return the same."
Contest - To run in an election.
Intimated - Contacted personally.  "You will be intimated by customer service shortly."
Haan - Pronounced like a nasal ha, it means 'yes'.  Usually 'haan, haan, haan'.  Okay, okay, okay.  Acha, acha, acha.
Bas or ho gaya - Enough.
Chelo - Let's go.
Peg - A shot of liquor.
Coolers - Sunglasses.
Cousin-brother and cousin-sister -  Just being gender specific, I think.  There are a lot of these compound familial relation descriptors.
Eck, do, teen - One, two, three.  You don't really need to know more than that, do you?
Lakh and crore - Hundred thousand and ten million, respectively.  "You totally want to have like one crore of his babies."
Double/triple - As in 'our phone number is 8408271 tripple 9' (that is not our number).  Or 'No, see in this case is spelled s double e.'
Only - Along with its usual meaning, used instead of 'just' and often at the end of the sentence.  "How's the concert so far?"  "I don't know.  I got here only."
Gymming - Going to the gym.  "You look great.  Have you been gymming?"
Mugging - To memorize.
To pass out - To graduate. 
Rubber - Some of them are really just British English.  Like duster for blackboard eraser and shift for moving house.  When the students ask me for a rubber, I'm pretty sure they want an eraser and not a condom.