Yes, the municipal authority are out of tds provision because their income is exempt. Since in your case the issue is Rent , no tax should be deducted. This was clarified by a CBDT Circular no 699 dt 30/1/1995 which states as under:
4. In view of the aforesaid, there is no requirement to deduct income-tax at source on income by way of ‘rent’ if the payee is the Government. In the case of the local authorities and the statutory authorities referred to in para 3 of this circular, there will be no requirement to deduct income-tax at source from income by way of rent if the person responsible for paying it is satisfied about their tax-exempt status under clause (20) or (20A) of section 10 on the basis of a certificate to this effect given by the said authorities.
Complete circular can be downloaded from here.
