Hello Ajay !

NAAC has certain guidelines for ranking colleges , for private colleges the eligibility criteria to be NAAC recognized are :

1. The Institutions /Deemed to-be Universities and their off campuses if any are approved by MHRD/UGC. NAAC will not consider the unapproved off-campuses for A&A.
2. The institutions must have regular students enrolled in to the full time teaching and Research programmes offered on campus.
3. Also ,  the duly established campuses within the country, if any, shall be treated as part of the Universities of National Importance for the A&A process.
4. NAAC will not undertake the accreditation of off-shore campuses

There are other eligibility criteria also , but if any college dose not meet these criteria then it is not recognized by NAAC ranking ,

You can check if you want more about NAAC eligibility , grading system and other on following site :

http://www.naac.gov.in/assessment-accreditation

Hope it helps !