Sec.22(1) Every supplier shall be liable to be registered under this Act in the State or Union territory, other than special category States, from where he makes a taxable supply of goods or services or both, if his aggregate turnover in a financial year exceeds twenty lakh rupees:
The above provides for registration of a taxpayer under GST if his turnover exceeds the threshold limit.
Sec. 24 : Notwithstanding anything contained in sub-section (1) of section 22, the following categories of persons shall be required to be registered under this Act,–
(i) ......
(ii) .......
(iii) persons who are required to pay tax under reverse charge;
This section provides that even if the turnover is less than the threshold limit the taxpayer is required to take registration if he is liable to pay tax under reverse charge.
In view of the above provision I interpreted that registration is required. However, thanks to expert colleague to clarify that this provision is not applicable as the RCM notification says that only registered recipient will be liable to pay tax under RCM for security service. Since the society is not registered the RCM notificaiton is not applicable.