What are the different modes of implementation of CSR activities?

Pursuant to rule 4 of the Companies (CSR Policy) Rules, 2014 a company may undertake CSR activities through following three modes of implementation: 

(1)Implementation by the company itself 

(2)Implementation  through eligible implementing agencies as prescribed under sub-rule (1) of rule 4. 

(3)Implementation in collaboration with one or more companies as prescribed under sub-rule (4) of rule 4.