Can I join a client full-time?

Hey Guys, I am leaving my current small consulting firm because I have multiple job offers - my NP is done. I told my US based client - that I have worked for over 4 years - that I am leaving. They did not want to lose me so they decided to send me an offer for double my current salary that I am tempted to accept. Will this cause any issues with my current company? Are 60 MONTH non-competes enforceable in India? What should I do since its an amazing opportunity.

Thanks!