UPSC

You are advised to complete your graduation to take civil services examination. You may choose subjects of your interests to succeed in the career. Subjects such as economics, political science, anthropology etc. are good subjects to appear in Civil Services Examination.

You must choose subjects based on your strength area to crack civil services examination.

Dear,
My thinking in respect of study is - when a course you will pursue, do seriously with your best effort after fixing a target and timeline. Both MBA and IAS require regular,methodical and extensive study. Do one by one. First, go for MBA in regular mode from renowned B-School after cracking management entrance test. Complete MBA , accept placement, if offered. Then try for IAS, your ultimate goal. Join coaching centre and you'll see , entire journey of education along with your work experience, makes you more knowledgeable , confident and give you an extra edge to reach your target. Best Wishes.

Dear,
Yes, you are eligible for upscale exam because any student who did Bachelor degree from a recognised university can apply for UPSC exam.
But, you need to work hard and maintain the time table.
All the best.

Dear Parul,
The best books to prepare for UPSC are:-
Indian polity by Laxmikanth
Geography of India by Majid Husain
Indian Economy by Ramesh Singh
A brief history of modern India by Spectrum
General Studies based on NCERT Syllabus
Certificate Physical and Human Geography.

Yes, any recognized university's degree is valid to appear for UPSC exam.

If you are planning to appear for civil services examination conducted UPSC after completing engineering degree, then your job profile as an IAS, IPS or IFS, etc. will not have engineering roles and responsibilities.
Aerospace engineers does not have dedicated cadre in Indian Engineering Services Examination conducted by UPSC.

Yes, You can do it after engineering.
Through the distance mode: IGNOU
If you want to do in some prestigious institutions:
By joining in college: JNU in SSS(School of Social Sciences) or SIS (School of International Studies). The latter will focus more on IR.
There are many other good institutes like DU, Central Universities soon. For both of these after applying you have to write an entrance test.

To appear for the UPSC exam, you need to first complete graduation. The minimum eligibility criteria to take UPSC is graduation degree. So, first complete your graduation then you can sit for UPSC.

For Master's degree, you can go for engineering or MBA. You can choose your Master's degree according to your interest. M.Tech would be better as through GATE you can apply for government jobs.