1)tenant is only a nominal member of the society . nominal member does not have parking rights
2) you have not mentioned how many parking slots are there in society ? how many members in the society ?
3) how was allotment of parking slot done by society?
4) whether each member has one parking slot ?
5) if number of members are more and parking slots less then decision of society would be correct .
6) if however each member has a slot then you can challenge decision of society before cooperative court .