Mathematics 3 or M3 in Engineering is a bit complicated but it can be explained. To tackle this subject, find a proper coaching centre to help you get accustomed to the syllabus. This will ultimately help you understand the concepts and techniques. 

Gadge Nagar is known to have good coaching centers. After learning the concepts in the class it is your duty to practice them for at least 1 hour.

SGBAUs syllabus is comparatively easier to manage and complete, so do not worry as you will be able to score better than the passing marks.