BCA

BCA is a good course and has job opportunities in IT sector.

The job of a Pilot/ Co-pilot is very challenging as well as rewarding. There are three licenses, which you have to acquire to become a pilot.
1. Students Pilot License.
2. Private Pilot License.
3. The Hobby License or Commercial Pilot License.

If you want to get a job in law field, then you must pursue BL, and then cyber law.
Master's program in cyber law and information security (MPCLIS) is offered at Indian Institute of Information Technology – Allahabad, which is open for BE, B.Tech, postgraduates, LLB or equivalent.
1. NALSAR University of Law.
2. Jitendra Chauhan College of Law.
3. Asian School of Cyber Laws – Pune.
4. Centre for Distance Education, University of Hyderabad.

Diploma after 12th won't make much sense. In my opinion, you should opt for engineering considering the fact that it has more industry value as compared to BCA and high pay package plus better future career options.

You can go for MCA through distance learning. Many recognised institutions offer this distance learning programme. You can opt for any of that as per your choice.

Tourism and travel industry is booming in India and there will be plenty of opportunities. With your computer knowledge, you will get a promising job after completing the course.

If the technical field interests you, then MCA is a good option. If the management field interests you, then MBA (IT) is an ideal option.

There is no embargo on doing job while doing part time BCA. You may face challenges in balancing time between studies, job and personal life.

B.Tech is a better option considering the following points:
1. B.Tech is always considered a better qualification than B.Sc.
2. B.Tech will help you in many ways as it opens more & better options for further studies and job opportunities.
3. B.Tech give you knowledge on the theory, practical & applied science where as B.Sc. is just theoretical.
4. There is good growth & salary difference all through your career.
5. B.Sc. is good if you interest is in teaching or general type of jobs such as admin, bank, sales, etc. But in these areas also in many cases engineering graduates are preferred.

B.Tech is always a better option as compared to BCA. B.Tech is equivalent to MCA.