after how many teaching years experience does an assistant professor become associate professor in college affiliated to Mumbai University
If you see the official notification as per University of Mumbai then it states -
Qualification as above that is for the post of Assistant Professor, as applicable and PHD or equivalent, in appropriate Discipline Post PhD publication and guiding PhD student is highly desirable.
Experience required:
Minimum of 5 years experience in teaching and /or research and /or industry of which at least 2 years shall be post PhD is desirable. In case of Architecture, Professional Practice of 5 years as certified by the Council of Architecture shall also be considered valid.
You can type on Google Search 'associate professor eligibility in mumbai university'. Hopefully you will get the pdf version from University of Mumbai Archives in the first recommend website. If not scroll down you will find it out.
I hope my answer helps. All the very best for your future endeavors!