Input tax credit

current 3b if goods vehicle

You can't, because as per section 16 of cgst act, the maximum time limit to avail the ITC is earlier of following:
Due date of filing next year September month return i.e. 20-10-18
or Filing of Annual return.
and when you bought the vehicle, what treatment had you made because if you already capitalized the whole amount which includes gst also then you are also claiming depreciation on such amount. so, not by ITC but you are getting deduction through depreciation.

@ Shivam Kohli.,

What is Your business...?
What are the uses of the vehicle...?

@ kishor lulla sir please elaborate.

@ RAJA PM My business is petrol pump business and vehicle is tank truck lorry to transport petrol and diesel

if truck used in transportation of petrol then no ITC can be availed as per rule 43