At present societies are registered in Societies Registration Act, 1860. It a state level and central level registration. Many states have adopted the Societies Registration Act,1860 and amended it according to their requirement.
The basic document of any society is its Memorandum of Association and Rules and Regulations.
Atleast 7 Members are required for incorporation of any state level of society, there is no upper limit.
The Objects are Literary, Charitable, Scientific and resource oriented etc.