Gst on sale of old car used in business by an advocate

Dear Sir,

Since Service of Advocate is under RCM u/s 9(3), and not required to take the registration.

An Advocate having gross receipts of 50 Lakh if sell his Old BMW Worth Rs. 25 Lakh , what will be Implication of GST on Advocate?
Will he required to pay GST on Sale of Old Card used for his Business Purpose?

What will be implication of GST on Medical Practitioner (Dr.) Having gross receipts of Rs. 50 Lakh which is exempted from GST sell his old car used in business worth Rs. 25 Lakh?