Hy Praveen!! 

The selection of  your course entirely depends on your interest. Don't demoralize yourself by thinking you are an average student , every student has his own strength. You should look for your strength and select the course accordingly.

You can do ba (it is easy ) or b.com and then go for banking line . 

If you are interested in drawing , BVA is also a good option. You need not to study much in this course.

If your speaking ability is nice , you cam try mass communication.

If you want to do business , go for BBA it really has good scope .

You can apply for SSC CHSL or LIC AAO , after taking either ba or b.com. these exams are a bit easier than other exams. 

SSC CHSL you can give after your 12th also

Hope it helps!! 

Good luck !!