Dear Sir,
Your query is not clear. I consider your problem in points and take relevant solution as applied to you :-
1) From your query it is considered that you let out your property from the month of June, on the basis of this your service tax liability is assuming mother is owner and receiver of rent and legal heirs received rent on the behalf of your mother without modifying rent deed, and rent remains same, then your liability is to pay (1300000/4*7) = (2275000-1000000)*15/100=191250 and you have paid 168117 and remaining amount to pay is 23133
The legal heir who receive the rent shall be responsible to pay this liability.
2) If after the death of mother all the legal heirs become the owner of the property and rent deed is modified accordingly then there is no service tax liability on part of legal heirs till each receive share of rent exceeding 10.00 lakh. Hence, you can claim service tax refund from department of an amount rs. 123117 along with interest provided you shall have to pay back this amount of service tax to tenant.
3) You may surrender the license within thirty days of closing to provide service provided all the service tax has been paid and nothing is due.