Hello Dear,

You haven't mentioned the State in which NEET Counseling you want to know. If you do not fill the Status retention form, the seat will not be retained and then you get to participate in the Mop Up Round.

According to the admission brochure.

"A candidate who is selected in first or subsequent round of selection process but does not join the college or cancels the admission after joining, it will be presumed that such a candidate is not interested in the admission process and for all further CAP round(s) including MOPUP round(s) of admission. Such candidate shall not be considered for allotment of any seat during NEET UG 2020 admission process through CAP round.

Good Luck