Dear sri software,
As per value added tax, any person doing mfg or trading activities has to be registered under the state act (VAT) & if he is doing interstate business then he has to get registered under cst act, 1956.
If he is doing business & if he is having office in more than one state, then he/she has to get registered under each state. In this case the place of business is the criteria. in any case he has to inform the local vat office for the other unit which is situated in other state.
TIN: means Tax Indentification No.
Example: I m doing business in Kar & Mah both places & having the registered off in both places, then wat ever i do business in kar, vat will be applicable as per KVAT & sale of product in Mah. Mah vat will be applicable. In both cases, if i m selling goods to other neighbour states like chennai, hyd then i m liable to be registered under cst act.
if u have any doubt, let me know