Cognizant — HR is asking Form 16 for my closed companies which I didn't receive it from past companies but I do have bank statements

After clearing L1 and L2 technical rounds I have recy a call from HR, He asked me to provide form 16 for past companies. I said him cleary i can provide form 16 for whichever companies provided to me, but very old companies they didn't provide Form 16 and they haven't deducted TDS so if you want I can share the bank statements. But HR said He can't process the offer letter without Form 16. I don't understand one thing, before scheduling L1 & L2 technical they should have asked me that i have form16 Or not, what is the point of asking at the end of HR round and not responding and rolling out offer letter.

Please help me on the offer letter process.