Help me with notice period

I am in a situation where I am facing a horrible 90 day notice period at my current organization.

I will be receiving an offer, maybe in a while, from HCL. I have never told the HCL HR that I have a 90 day notice period.

HCL completed the client interview too. I will be having one negotiation round. I don't know how to deal with it. It's going to be my first switch, and I'm scared.

How to deal with this 90 days? Should I lie to HCL HR? I don't know how to deal... please help.