Diploma

Yes, if you meet the requirements. You can pursue studies in a desired field as long as you know what you want and have clarity over your future plans.

Dear Mandeep, look for Bachelor's degree program in mechanical engineering or any field of your choice. What you have to study is entirely your choice, aeropace, automotive design, robotics, mechatronics are some specializations within the field of mechanical engineering, which one do you like more.

Any guarantee from my side or from anybody would be misleading. Getting a job is no guarantee. You need to check job portals, find out the requirements, profiles, vacancies, if they have positions open fitting your profile you can apply. How you face the interview, your qualifications and additional

Hello Happy Sakar, Thanks for asking,
You can opt government jobs like
IBPS
RRB
SSC and many other.
You can go for RRB Exam because railway is the largest recruiter in India and now a days there are many vacancies in Railway because railway is suffering from staff shortage.
You may check all the updates

Kindly elaborate your question please. What do you mean by Valid?

It is definitely an diploma, there is no degree less than 3 years

You may evaluate GGSIP university weekend MBA program.