Your actual ITC won't change based on these things. Your actual ITC will be 136. However, coming to the part eligibility of ITC, as you had shown Rs. 150 ITC in GSTR 3B, then you can claim Rs. 150 as your ITC if the ITC amount of one of your supplier who had not shown the bill in his GSTR 1 is less than 20% of your total ITC. Maximum difference that can be allowed in GST is 20% limit for the period prior to 01st january 2020.
However, it is advisable for you to ask the other party to file GSTR-1 to avoid future complications.
Alternatively, you can pay back the government such amount with interest and recover the same from the client
So, in 6a it will automatically autopopulate as 160
In 6b show 136.
in 6m show 14
If the difference is less than 20% and you had not paid back to the government of that one client, then no need to do anything but if you paid the same then show the same in Reversal column