First of all you need to lose this ideology that ECE has more scope and mechanical or aerospace engineering has less scope. Every field has top notch research going in it and provides dynamic and challenging work opportunities.
I also had the same dilemma and I chose Aerospace engineering at IIT Madras over other departments due to following reasons:-
It is tough to compare IIT Kanpur, IIT Madras, and IIT BHU as all of them are ruptured old and top institutes of India. Here are some key points that you should consider while choosing a particular institution:
Overall, consider IIT Kanpur over IIT BHU, and IIT Madras. Although it depends on personal choice.
It’s highly illogical to compare to diverse branches like Mechanical, ECE, and Aerospace engineering. The best way to determine the better one is to analyze your own inclinations and find out which field intrigues you the most.
If you are interested in Aerospace Engineering, then choose IIT Kanpur over IIT Madras. IIT Kanpur is well known for the best Aerospace Engineering department in India.
But if you are interested in ME or ECE, then choose IIT BHU. In fact, you can get these branches in IIT Kanpur through branch upgradation. All you need to do is work hard till 4th semester and score excellent marks. IIT Kanpur is among the top 5 IITs so obviously it’s a better deal than IIT BHU.
The choice should be based on the branch you are interested in. Among all the branches mentioned in the question, Electronics is the one highly ranked concerning the opportunities available in the industry. Also, Electronics is the most sought branch in IIT BHU along with CSE. According to 2019 placement statistics out of 100 students from the electronics engineering branch, 88 got placed.
Mechanical Engineering ranks a bit low in IIT BHU in comparison to Electronics. Though Mechanical Engineers find several opportunities in the form of PSUs and government organizations in India. In 2019 placement drive 109 students from the mechanical engineering department got placed. The average CTC offered in IIT BHU was around 8.19 lakhs.
Aerospace engineers in India have very limited opportunities after graduation Aerospace Engineering department at IIT Madras has good opportunities and exposure in comparison to many institutes in India. Hindustan Aeronautics Limited and Indian Space Research Organisation also hail from the southern part of India and this might help in the placement procedure though several students look for non- core opportunities or Masters in Design Engineering for a better future in India. When placements are concerned, IIT Madras has a slight edge over IIT Kanpur. As far as foreign universities are concerned, many students get summer internships abroad in the USA, Germany, Russia, France, and Italy from both the institutes. Many students go for MS and Ph.D. programs in esteemed Universities like the University of Maryland, Stanford University, Purdue University, etc. Though getting internships and foreign university admissions entirely depend on how hard one works irrespective of which IIT they belong to.