What are the documents other than salary slips and form16 that CTS accepts as proof of salary?

What are the documents other than salary slips and form16 that CTS accepts as proof of salary for background verification? Does offer of employment from previous employer sufficient as proof of salary and releiving letter as proof of my employment?
I dont have salary slips and form 16 from my previous employer.So, does offer of employment and releiving letter from my previous employer sufficient to prove my employement to CTS background verification?

Hi Kapil,
Background verification you can submit Bank Statement (Where your salary is credited) along with offer letter and appointment letter. Request your HR to provide salary slip if possible.

Thank you praveen for the information....
I have also query to clarify...I have got the offer letter from CTS and background verification is going on..I have 17 months 11 days of experience,,so i rounded it off to 18 months and statedthe that i have 18 months of experience...does this effect my BGV....does 20 days less matters?????