Got offer from TCS 12LPA, 3.5 YOE. Tech: Oracle EBS/Apps developer. Current CTC 6.5 Infosys. Is it ok to join TCS?

If you are looking for learning and growth then don't join tcs, just take the offer and go some other mid level or product companies, I made the same mistake with something similar offer joined tcs and from then completely stopped my growth, I never got opportunity in tcs to do development all are just maintenance project. I still regret my decision of joining tcs early in my career

I had 2 technical rounds at TCS, and today they asked me to upload documents. How long does it usually take for them to process the documents and release the offer letter?

Yess

Yes