Government & Defence Entrance Exam

Continue studying your class 11th and class 12th Maths carefully. Revise all the NCERT Questions of the books. Get a preparation book for NDA Exam like Pathfinder by Arihant, Upkar, and other publications.

Hi Junaid,
For preparation of IAS and UPSC, I would prefer you study subjects such as History, Economics, and Geography which will make you competent for the exam.
Good luck.

Your becoming of an IAS is not depended on our comment on your question it depends on your efforts, hardwork and your intelligence. So prepare well for IAS exam.

Yes, you can apply for government job and start preparation.

Yes, it's degree is valid, as it is a national University.

After completion of your class 12th, you can join Indian army as a soldier. Just fill your form online or join Indian army, as per your district rally and go to the rally and participate in the physical test of Indian army.

Hello,
The Railways Exam is conducted for different posts in Railways. Including the technical and Non Technical Posts. One of the post in Railways is RRB ALP or Assistant Loco Pilot Exam. Recently the government. And RRB Board has recruited the various candidates for the Railways Assistant Loco Pilot Exam. The RRB ALP Exam would be conducted in different phases of Computer Based Test. You can prepare for the RRB ALP Exam check out the Syllabus-https://scoop.eduncle.com/rrb-syllabus-exam-pattern of RRB as the Exam is conducted in the given subjects -
Mathematics
Technical Ability
General Awareness
Arithmetic
Reasoning Ability.

PG Degree is the best and rational choice for you. I don't mean to discourage you but see that you are at 30 and a degree of PG will strengthen your career efforts. Whole doing PG, you can keep your preparation for UPSC on. But I shall not put your UPSC aspirations first over Higher Studies.

Below link may help you:
https://www.quora.com/What-are-the-salaries-of-IAS-IPS-and-IFS-officers.