supply of capital assets

As per the definition of supply u/s 7 of CGST Act if you have made such supply in the course of or furtherance of business and for consideration irrespective of the fact that you have not availed the credit, it will qualify for the definition of supply. So gst will be leviable.
However if you have supplied without consideration and have not availed the ITC then gst will not be leviable as per sec 7 of CGST Act read with schedule 1 to the same section. As it will be a permanent transfer of business assets on which itc has not been availed.