Sale of vehicle

sir GST applicable on sale of old vehicle. for new vehicle unless you are into the business of Vehicle hire you cannot claim input.

not hire, own business use
vehicle sold less than book value

GST applicable irrespective of book value on resale. own use no gst input

As per Notification 8/2018 CT (R) ,
GST on vehicle purchase & No ITC Claim (Or of Vat Regime) , will be on Purchase value (Book Value) Minus Transaction Value .

Hence in your case No GST is Applicable because vehicle sold less than book value

GST applicable on sale of old vehicle. for new vehicle you are into the business of Vehicle you cannot claim input. 

As per Notification 8/2018 CT (r)

Vehicle of Vat Regime Sold in GST Regime :
GST is applicable on Profit Margin (Sale-Puchase )

Vehicle Purchased & Sold in GST Regime :
If ITC claim , then GST is on transaction Value 
If ITC is not claim , then GST is on Profit Margin (Sale - Purchase)

GST Rate 12 % & 18% is applicable as per CC engine of vehicle mentioned in Notification.

More then 1500 CC , leanth exceeding 4000 MM, GST is 18%

Else ,.. 12%

So , calculate your Gst payable on sale of vehicle as per above said notification