Hi Gautam
It depends on the BTA (Business Transfer Agreement) entered into between your Company and the Seller Factory. Some Companies keep the legal identity separately even after purchase in which case, you have to continue to comply with the applicable Labour Laws of the Seller factory.
If it is an amalgamation or merger, then you have to get your existing factory other licenses changed and surrender the licenses of the seller factory.
Regards
P.S.Lakshmanan
S.G. Management Services
(PAN INDIA Labour Law compliance specialist
P.F. ESI, P Tax, Benefit Management &
POSH COMPLIANCE)
Kolkata