Employer is holding my salary

I was working in a startup from last 1 and half month from 25th jan 2024 to 5th March 2024. On 5th March they came and said they are not happy with my performance and they don't want to continue with me. They never given any verbal or written warning to me and on asking what is the lag in my performance they don't had any proper answer. I know that I have performed well because I have given good results to them. Even after that they demanded forced resignation from me after building mental pressure giving direct threats to me on call. I tendered my resignation but they have not paid my salary. I worked there for 1 month 12 days plus 15 days notice period. I have the company laptop with me whose valuation would be around INR 20k. Now they are saying to submit the laptop first and then they will release my 1 month 7 days salary (INR 74k)(from 25th jan to feb end) and they will process the remaining 20 days salary(INR 40K) in the next cycle but I have a doubt on this due to which I want hold back their laptop with me and I am proposing to return their laptop after the clearance of all dues. I am also demanding one time settlement of dues but they are not okay with my proposal. Now please tell me what should I do?