Service tax credit for service tax paid on commercial rent

yes you can take credit.

i hope you are franchisee of some brand and register under service tax

Yes, if you are already registered with service tax department and filing return on scheduled time and paying service tax. If the service tax paid is related to performing main business activity and nature of expenses is such that it can be associated with main business. In this case rental paid to landlord is the expense incured to run the business so absolutely credit can be taken on the service tax paid with rental.

For availing CENVAT credit of tax paid on input services you should be registered with Service Tax Authorities. CENVAT credit can be availed for payment of Service tax on taxable output services.

But as you are in trading business and not providing any taxable service(I assume its not a franchise) you can not register under Service Tax Act 1994.

So no, you cannot avail credit of Service. But you should get a TAN no. if you pay commission to agents if you're a firm or company or individual/HUF liable for tax audit.

The Cevat Credit rules - especially Rule 6 maybe examined in detail. You wouldbe eligible for proportianet credit as per Rule 6(3). You may not be eligible for the entire credit on the logic that the trading part also requires space on which no ST is payable..

But when there are both taxable and exempted services provided from a Exempted Input service then rule 6(3) apply

But there is another issue

The issue for consideretion here is service is used for both trading business as well as for taxable service so rure 6 (3) is not applicable here