GST rate from 5 to 12

MOHIT LODHI (24 Points)

22 March 2023  
In the case of renting of motor vehicle (SAC 9966), the taxpayer opted the tax rate from 5% (not eligible for ITC) to 12% (eligible to claim ITC) from FY 2023–24, so can he claim the ITC on input goods held in stock and capital goods?
If yes, then through which form?