Yes, your should take legal option against the company.
You have a very big chance to win the case.
You will secure you job during your leave (at least 6 moth by CA status law)
. And they have to pay for your lawyer fee plus some money for your "suffers
" in this bad lay off process.
Don't sign anything with the company and keep (save) you mail as an evidence
. Find a lawyer ASAP and dont let HR to know it. Now they are just trying to
let you resign by your own self by transfer you visa to another company. In
this way they will have a legal ground to proof they are not laying off you
. And you will lose the case for sure.