Guaranteeing pending salaries and rights at the end of labour contract

Hi,

I am Z. A.

My employer is not paying my salary for 3 months now plus another pending amount, and my contract is expiring on 8th May 2019.

I got an offer letter from another company and I resigned from my job.

My query is if my employer does not cancel me after one month or if he does not pay all my dues, what should I do to get cancelled and get my dues paid without losing the new job offer?

Please help me out.

Best Regards,

Z. A.