Supply of services

Mamta Batra (Chartered Accountants) (28 Points)

07 July 2017  
We are an Event management company having registered office at delhi and branch office at Mumbai. The branch office only promote the business activities of the company. All invoices are issued from Delhi office. Now my query is that what would be the place of supply of services in case event takes place in Mumbai, will it be Mumbai or Delhi?
for event we hire hotels or exhibition centres?