Procedure in case employer not relieving before duration in bond

Hi sir, I have been with the current company for the past 4.5yrs,i have not been given any promotion or recognition.I got a better opportunity hence resigned on 19th july 2017.then my employer happened to revise my package as an act of retention, subsequently i revoked my resignation on 21st august. I again got a even better opportunity after a week of my withdrawal of my resignation, once again i put down my papers on 29th august after which my revised package also was witheld. My actual notice period is 90days whereas new employer is asking me to join in 60days if not the offer is not valid.Had a discussion with the employer who is not ready to relieve me before 90days.As per my agreement on notice period clause at the time of joining is as below : "Your employment is subject to termination by either party by giving 90days notice or 90days salary in lieu of notice period" Kindly advice me how can i move further. Please help. Awaiting your reply.