1. Get an official mail from HR's mail id about your appointment etc. That should suffice;
2. If possible try to have something printed on Company's Letterhead about salary etc. This will be better proof;
3. Simply ask for receipt for cash atleast and the TDS calculations made for any deductions made;
4. In case receipt or calculation is denied, simply write up whole thing on paper and get it stamped and signed preferbaly ( or either of them) to authenticate the salary thing
Above steps should resolve the confusion and problems.
13th July 2013 From India, Gurgaon
23rd July 2013 From India, Hyderabad