Trending @HCL; Mainframe or Java Development 3+ years experience

Hi Guys, I have been in HCL for more than 3 years now, and have joined here as a Fresher.

They gave training in Java Full Stack with React Js for 6 months. Then, they kept the project bench for another 6 months.

Then, they gave training in Mainframe and deployed in the project and worked here for 2 years in this.

Timings of work are insane. In the morning we start with the Batch Cycle by 7:30 A.M. And Development work starts at 10 A.M., Evening handoff call at 7 P.M., which goes till 10 P.M. Sometimes we have to work till 3 A.M. This is Full RTO.

My salary also didn't cross 5 LPA.

How to switch to other companies, I am not getting enough time for preparation and sleep.

Should I get well prepared for a few months and move to Java Domain. Or switch to the same Mainframe.

How are people even handling 90 days notice period???