kindly also go through the NON - COMPETENCY and NON - DISCLOSURE clause of your agreement. the company may restrain you from serving another company based on these clauses.
so, please go slow. go through your agreement and do not take any decision without consulting any competent lawyer.
You can always pursue any good opportunity provided that you convince the employer you are not well and unable to continue the job-to quit. And if the new employer you have found out is willing to provide a visa for you to US,you can come back to India and go on a new visa and join them back in US.