Firstly Congratulations for getting GC!!

There is no reason to hang on with the employer after getting GC. Uddta panchi ho GC paye pachi, you are free to do what ever you like, not crime hai feri haha.

My experience: I already had GC but I joined employer/consultancy and also signed 1 year contract to tie up with them. I took training with them and they provided me accomodation also. After training was complete I ran away and didn't work with them at all. Nothing happened at all, they didn't do anything. By now its been already over an year.

So no problem dude, if you find another better opportunity, you can leave that employer. They have already got lot more than they deserved from you. Its time to say good bye!!