Does my retention letter clause stand valid?

I joined a company in July 2019. My compensation was 7.75L + fixed one-time bonus of 1.25L Three months later, in October 2019, I asked for a hike. They gave me a retention bonus of 1L and added my one time bonus of 1.25L to my fixed 7.75L making my CTC as 9L + 1L retention bonus. Now the terms of retention bonus were that I cannot leave the company before March 2021. If I leave or if I am terminated, I will have to pay the money back. When Covid struck, the company decided to do a pay cut for six months. When the pay cut was announced, the company sent a letter again stating that all the old clauses on notice period stand invalid and if you want to quit, you will have to give one month notice or one month's pay. Now they have put me on notice for poor performance despite working hard. I am asking them on clarity for retention bonus or what happens after my probation but they aren't answering. So I started seeking other options and have finally found one. I want to quit now. Will my retention letter stand valid in this case?