See there are no official information regarding this. But in general there can be two possibilities:

• The marks will be allotted to the students as per the rules designated for the regular 2021-22 HSC students.
• As the situation improves, the class improvement examinations will be organized after the release of HSC results 2021-22.

As there is no official notification any can't be said with absolute confidence.

You can contact the HSC board members as per the number provided in the official website and get it confirmed. This can be a great way out.

For the contact details you may visit the link below:

http://mahahsscboard.org/contact.htm

I hope this answer helps.