Got placed in TCS, received the offer letter but still waiting for joining date. What should I do now?

So i got placed in TCS and have already received my offer letter. But I’m still waiting for my joining letter/date, and honestly, I’m not sure how long it’s going to take.

I’ve heard from some of my seniors and also seen other people mention that TCS sometimes takes quite a long time to send the joining letter after giving the offer letter. Because of this, I’m getting a bit nervous and unsure about what I should do now.

Should I start looking for internships or other jobs in the meantime? Or should I just focus on upskilling myself and preparing for when I eventually join TCS?

The main problem is that I don’t have a clear timeline, and because of that my productivity has also been going down day by day. I keep thinking about what I should do, but then end up not doing much.

For people who have been in a similar situation, what did you do while waiting for your joining date?

Should I continue applying for other opportunities just in case, or focus on learning and improving my skills ?