Partnership firm

The Companies Act, 2013
As per Section 464 (Prohibition of Association or Partnership of Persons Exceeding Certain Number) of the act.
Excerpt: No association or partnership consisting of more than such number of persons as may be prescribed ....
Provided that the number of persons which may be prescribed under this sub-section shall not exceed one hundred..
Further, Rule 10 of Companies (Misllaneous) Rules, 2014, the limit prescribed is of 50 members.
So if you have a Partnership firm with more than 50 partners, then it will be deemded to be an illegal association of persons as per the current provisions.
Hence the maximum number of partners for a partnership firm can be concluded as 50.