Hi Harshavardhan!

There is no need to prepare other branch's syllabus for Railway Recruitment Board Junior Engineer Exam! However both CBT 1 and 2 comprises of Maths, General Intelligence and Reasoning, General Awareness and General Science, Chemistry, Physics and other knowledge, so it will not differ much. So, just concentrate on your syllabus and that is enough!

Hope this is helpful!

All the best!