Hello Aspirant

In order to become an Assistant Professor, you need to clear your NET exam and secure the percentile that is optimum for your category (General, OBC, SC/ST, etc.). If you have cleared the NET exam, which you have from Painting, then yes, you are eligible for the post of assistant professor in any college.

No, your background in BSc will not pose a problem in your job interviews that will give your resume a boost. Before applying to universities/colleges for jobs, read their guidelines and requirements because some universities demand work experience from their candidates. Rest is all fine and clearing NET is a big deal, so make good use of it.

All the best!