ITC CLAIM OF Previous Months

MD TECHNOLOGIES (59 Points)

18 January 2021  
My GST consultant did not claimed ITC from April, 2020 till June,2020 even when shown in GSTR2B of that month, however he claimed ITC of the September, December month.
1. So can I claim the ITC of those months in the GSTR3B of December,2020?
2. If so how?