Sorry to disappoint you but you can not write compartment exam for more than 1 subject.
And about you want to take drop that depends on you.
There is always another chance
you can have full details on the cbse website.
Here is an piece of text from the original file about imporvement of performance
RULE 44.1 IMPROVEMENT OF PERFORMANCE - SENIOR SCHOOL
CERTIFICATE EXAMINATION
AMENDED RULE 44.1(i) : A candidate who has passed an examination of the Board may
reappear for improvement of performance in the succeeding year only; however, a candidate who
has passed an examination of the Board under Vocational Scheme may reappear for improvement
of performance in the main examination in the succeeding year or the following year provided they
have not pursued higher studies in the mean time. They will appear as private candidates. Those
reappearing for the whole examination may, however, appear as regular candidates also if admitted
by the school as regular students. The candidate (s) appearing for improvement of performance
can appear in the subject (s) only in which they have been declared pass and not in the subject in
which they have been declared fail.
iii) AMENDED RULE 44.1(iii): Candidates who appear for improvement of performance will be
issued only Statement of Marks reflecting the marks of the improvement examination.
ALL THE BEST!!!