Sub-lease is not a surrender of lease.

A sub-lease is a demise by a lessee for lessor term than he himself has. Every lessee, however short his term may be, make a sub-lease unless he is refrained by the contract of the tenancy from subletting. If the demise is for the whole term or for a period beyond the term, it amounts to assignment. If the lessee divests himself he becomes a stranger to the demised property and he has no right to have possession delivered up to him. It is true that a covenant against subletting will restrain the assignment, but a mere covenant against subletting does not prohibit underletting a part of the premises. As long as the lessee remains in possession he may permit another person to use the demised premises without committing a breach of covenant, namely not to assign, underlet or part with the possession of the demised premises. Surrender of lease is not a transfer but mere yielding up by the lessee of his interest under the lease to the lessor by mutual agreement. It is in effect merger of the estate of the lessee into the reversion. It is not a transfer or an assignment of any right or estate within the meaning of Section 5 of the Transfer of Property Act, 1882. The person who surrenders is called the surrenderer and the person to whom surrender is made is called the surrenderee. A Requisition Order by the Government does not amount to any surrender. It may be expressed or implied. Except in a case of some special kinds of lease as required by special Act, no writing or registration is necessary. Surrender may be oral, if accompanied by delivery of possession.