First IGST input of Rs 50 has to be fully utilized. CGST output of Rs 90 will be first set off with IGST input of Rs 50. Then balance CGST output of Rs 40 will be set off with CGST input of Rs 150. Now c/f under CGST is Rs 40/-.
SGST output is to be set off with SGST input. Balance c/f in SGST is Rs 60/-