I had acquired GSTIN registered with the proprietor's PAN who unfortunately has expired last month. Can I still run the business by changing the authorised signatory to the wife's name through an ammendment OR do I have to obtain a fresh registration.
Also if so (obtain fresh registration) what is the procedure for the same considering transfer of assets and liabilities
Since this is a proprietor, no one except proprietor has authority. The best way would be get the property transferred to the legal heir of the person. You need to consult lawyer for this purpose.