law: Companies Act, 1956
  Sec 11    -    
  
  Prohibition of associations and partnerships exceeding certain number. 
  (1) No company, association or partnership
  
  consisting of more than ten persons shall be formed for the purpose of carrying
  
  on the business of banking, unless it is registered as a company under this
  
  Act, or is formed in pursuance of some other Indian Law.
  (2) No company, association or partnership
  
  consisting of more than twenty persons shall be formed for the purpose of
  
  carrying on any other business that has for its object the acquisition of gain
  
  by the company, association or partnership, or by the individual members
  
  thereof, unless it is registered as a company under this Act, or is formed in
  
  pursuance of some other Indian law.
  (3) This section shall not apply to a joint
  
  family as such carrying on a business; and where a business is carried on by
  
  two or more joint families, in computing the number of persons for the purposes
  
  of sub-sections (1) and (2), minor members of such families shall be excluded.
  (4) Every member of a company, association or
  
  partnership carrying on business in contravention of this section shall be
  
  personally liable for all liabilities incurred in such business.
  (5) Every person who is a member of a company,
  
  association or partnership formed in contravention of this section shall be
  
  punishable with fine which may extend to ten thousand rupees.