Mr Magesh, generally a regs. co has innumerable operations in various states, thus, they obtain local TIN no in each state for operations. whatever you purchased from Bangaluru should certainly come under the ambit of local VAT, and the supplier is deemed to specify the Bangaluru "Local address"(which is mentioned for local VAT registration process) in the Bill raised to your Co.
However, he have raised a Bill in the name of H.O. at Delhi, which he can do so in either of following manner:
1) Raise a Relaxed CST Bill, against a C Form due from Delhi office OR
2) Raise a Normal CST Bill at High Rate, against which there is no needful to be done
Now, in either of case there is No possibility of any Input credit Booking because its a CST purchase, however in the second case, the material shall be more costly.
Thus, now you are suggested to check the invoice, to check CST value or Else its sure that the Invoice is a void ab initio, and hence request your supplier to raise a correct invoice, by the explanating the requisite specifications
Regards and Cheers