there is a person X supplier of service who is in Kolkata is taking a contract from person Y who is in mumbai.person y has 3 branches as A,B,C in Delhi, Kolkata, Mumbai respectively.
what all things will be applied in the above situation?
a) IGST,SGST,CGST
B) INVOICE,ISD
C) CTP,ITC
give me a detailed analysis of this situation please