I am currently holding a H1 with a Indian MNC employer but haven't travelled to US using that visa. Though had travelled 4 times before in different visas (L1B, B1 etc.)
If I change the job will my H1 visa get cancelled?

If you don't intend to work for the H-1B petitioner as an H-1B, they have an obligation to notify the USCIS and withdraw the LCA, via iCERT.