Yes, you can do provisional registration for CA Inter while in your final year of B.Com.
Since you have a backlog, you can choose the "Results Awaited" option during registration. However, you must clear all backlogs and submit your final B.Com pass marksheet within 6 months of registration.
If not submitted within this period, your registration may be cancelled.
Ensure regular review of ICAI guidelines and deadlines to maintain compliance.