It would depend on the contractual arrangement between you and the third party ie whether you are leasing out the restaurant or they are just managing on your behalf in return for management fee etc. It is necessary to identify who the supplier is for services rendered in the restaurant.

Dear Sajith, third party will be managing it for us and we intend to pay them management fees for their services.

Then they would be regarded as agents acting on your behalf. So the taxable supplies made from restaurant will be considered as rendered from your end and taxable supply of the management entity would be the fee they would charge you.