Partnership firm can be converted into a company. The procedure for conversion is governed by Section 366 of Companies Act and Companies (Authorised to Register) Rules 2014.
Limited Liability Partnership (LLP) Registration can be converted into a company as per the provisions contained in Section 366 of the Companies Act, 2013 and Company (Authorised to Register) Rules, 2014.
Conversion of Private Limited Company into Public Ltd Company involves AOA of Private Company u/s 14 which can't done without passing special resolution of Shareholders in General Meeting.
A public company may convert itself into a private company by taking approval of members by way of passing special resolution in the General Meeting and by taking the approval of Central Government