How can I pursue actuarial science? Is it a difficult course to complete for an average student? ?

You need to have good analytical reasoning and mathematics to be an actuary. There are in total 15 papers to clear to be successful. These subjects are grouped into 100 Series (CT), 200 Series (CA), 300 Series (ST) and 400 Series (SA). Rest of the info can be checked at http://www.actuariesindia.