I am currently in 2nd year of B.Tech and want to do start my MBA preparation, so syllabus of all MBA entrances be same for me when I appear?

Yes, to a large extent, the syllabus is common. However, the format could be different. In my view you should focus on your B.Tech and only start preparing for MBA open test in your forth year. A sincere effort of 3 to 4 months is enough for open tests. Joining a institute which trains for MBA open

The syllabus will remain same for all the MBA entrance exams. You have to prepare for CAT examination.

Yes, the syllabus for the entrance tests remains the same. Only the levels of questions differ. Each and every test has Logical Reasoning, Quantitative Aptitude (Mathematics), Verbal ability (English), General Awareness and Data interpretation.