Apply for GST registration while working in MNC

I am working in a reputed MNC, and want to start a online selling business totally unrealted to my prviate job. I have to apply for GST registration and use my documents like PAN card.

Have few questions in my mind which is restricting me from initiating the GST registration process:

1. Does my employer will come to know about my business with my PAN number ? (does this breach company's dual employment rules)

2. If this doesn't affect my current employment then in the near future if I decide to switch the company will this affect the background verification process (usually for background verification process we are supposed to submit last 6 months bank statement, PAN number, UAN number for PF and last year's ITR proof)