Sir even if there was a clause of lock in period then also you can ask only for reasonable loss and compensation that you have suffered you cannot ask an amount for the total period. This is clear position of law settled in many cases.
Compensation/ Damages is awarded to make good the losses suffered by the aggrieved party, so as to reinstate him in his original position. Law does not penalise a contracting party for a contractual breach and neither does it allow the aggrieved party to take advantage of such a situation. The rule is that the parties are free to breach the contract provided they compensate the other party, if the other party has incurred an actual loss due to such breach.
Therefore if the lock-in clause in a leave and license agreement states that, in case of breach of the said clause, the licensee is liable to pay the rent for the remaining lock-in period is not really enforceable in a court of law. Only a claim based on actual injury suffered by the aggrieved party can be made whereas he has to prove the following things to make a successful claim
That such amount claimed is a genuine estimate of damages,
That the landlord had altered its position by making the premises available to the licensee keeping in view the licensee’s requirements and spending thereupon. That certain expenditure was incurred on infrastructure specifically provided to the licensee as per licensee’s requirements; certain other expenditure incurred on whitewashing, fixture and fittings and the landlord was forced to incur expenditure again before giving the premises to the new licensee and , therefore, lock-in period was treated as reasonable period to avoid duplication of such expenditure, etc.
That the licensor took all reasonable steps to mitigate the loss consequent on the breach.
Quantifying the compensation/ damages for a breach of the lock-in commitment is unnecessary as by proving the above mentioned three points, the aggrieved party is only entitled to get a reasonable compensation based on the actual losses/ injury he has suffered and he is not entitled to the agreed quantified compensation amount. Thus mentioning a quantified compensation in the lock-in clause itself acts as a mere scaring provision unenforceable in the court of law.
The above findings were held by SC in Silvermoon Construction Pvt. Ltd. v. South Asian Hospitality Services Pvt. Ltd., MANU/DE/4958/2012
So in my opinion deduct reasonable amount from deposit along with rent and refund rest of amount to the tenant and settle issue. Further if you even go for specific performance of agreement the court shall grant only actual damages caused.