M.Tech

Hello Parth,
These two coaching institutes are best for GATE preparation:
1. The GATE Academy, Ahmedabad
No. 323, 3rd Floor, Sunrise Mall, Near Manasi Circle, Vastrapur, Ahmedabad, Gujarat 380015
2. Ice GATE Insitute
201, Sunrise Mall, 1st Floor, Near Mansi Circle, Vastrapur, Ahmedabad, Gujarat 380015
Al

Hello Lovely,
Please follow the link provided below for complete details about the books according to your branch form which you have done your B.Tech:
https://www.shiksha.com/engineering/articles/gate-books-blogId-21817

Hello,
Pursuing Aerospace Engineering as a specialization in Post Graduation (M.Tech) is indeed a better choice. Aerospace Engineering is a niche branch in India with limited job opportunities at present. However, since you already have completed Bachelors in Mechanical degree, you can apply for jobs

There are no more distance learning centers in North India. Here, I suggest better distances learning centers in India. you can choose any one of them:
Annamalai University
Amity University
IGNOU
Karnataka open University
Thapar Institute of Engineering and Technology
Mahatama Gandhi University