HCLTech Technical Architect interview questions

I had three technical interview 2 with senior technical architects and 1 with CTO of the cloud native architecture R & D labs in HCl for Noida location. I cleared all three rounds. After that I was asked about my salary expectations, I communicated to them, after that they asked to submit all documents for releasing the offer letter. But I never got any offer letter even after a month. I mailed them couple of times , but no response from their end which I found very