In Delhi University it can be anything, our friend circle had names like macchar(too slim), Phaavda(Big teeths), Balushahi(surname Balushi), tharki(natural), charsi(smoker), Billa(short heavy built), chopi(chopra) etc, sometimes these name were derived from surname, sometimes god knows what:D
Ninja can tell even better, these marathis shortens names wonderfully, Tendlukar becomes tendlya, etc:D
Tharki means natural 