No you can't give the improvement exam if

you have joined any course. The prerequisite

of giving the improvement exam is that the

concerned person must not be enrolled in

any course while applying for or giving the

exam



So, you can either join a course or you can

drop a year to give the CBSE improvement

exam the following year, whichever you are

comfortable with. Also if you lagged in just

one subject, there is an option which allows

you to give one exam the same year to

improve your score. This exam is usually

conducted by the CBSE along with those

appearing for compartment papers. But

again it depends on your choice to give the

exam or not as the results are announced late

around August when colleges seats are

occupied