Problem with Previous experiance

I worked in a govt organization for 3 years through a Vendor(who supply resource to govt organizations), the Vendor is not have any dedicated staff, the owner is the only one guy who manages all the resource(no website), post that company i managed to get a job in MNC where i worked for 6 years, now i would like to change my job.
i have the offer letter and pay slips from the first company but dont have the form 16 or bank statement as i used to get the salary from the envelope. How can i explain this to HR to process the BCG, could you please help me in this please.
Regards
Raja

Dear Raja,
Not in possession of Form 16 should not be a cause of worry. Were you income tax payer? If not, then why your company would have issued Form 16? Secondly, if you have paid the income tax, then you may provide the copy of the tax return and that too if asked for.
As far as payment of salary in the cash is concerned, you may tell that I had asked for salary through the bank however, you were told that disbursement of salary through cash was legally acceptable during that time.
Thanks,
Dinesh Divekar