Diploma

Hello,
It is very nice to see your enthusiasm even at the age of 36 to seek admission for Diploma in Engineering but unfortunately majority of the states have put a cap on maximum age upto which you can see admission to Diploma courses and this gap is invariably placed at 21 years. Thus it is clear that you will not be able to do Diploma in a regular college but perhaps you can think of doing it a distance mode education or doing degree directly by appearing to become associate member of Institution of Engineers which is equivalent to BE.
Best wishes.

Hi!
You can refer https://www.shiksha.com/business-management-studies/colleges/certificate-sales-marketing-colleges-kolkata

Hi!
No, the graduation is of minimum 3 years everywhere.

Hi!
There may be a provision for lateral entry. I would advise you to contact the institute directly for the information.

Hi!
Yes, if you fulfill the eligibility criteria given on this link, then you can apply https://www.shiksha.com/humanities-social-sciences/course/post-graduate-diploma-in-disability-studies-visva-bharati-university-west-bengal-other-269767

Hi!
Which exam are you asking about? Please give complete details for better guidance.

Hi,
Eligibility for Diploma in Nautical Science:
Admission is through counseling based on the rank obtained in Indian Maritime University Common Entrance Test (IMU-CET).
https://www.shiksha.com/science/course/diploma-in-nautical-science-indian-maritime-university-t-s-chanakya-navi-mumbai-276988
Eligibility for B.Sc. in Nautical Science:
https://www.shiksha.com/science/course/b-sc-in-nautical-science-indian-maritime-university-t-s-chanakya-navi-mumbai-276979

There are multiple job opportunities in this field. Depending upon individuals academic background along with working experience in taxation, employ can be found in all corners of the globe. Diploma in Taxation Law (DTL) graduates in this field can seek employment in government and private sectors. Candidates can join any industry as tax policy analyst, tax recruiter, tax advisory, tax examiners, revenue agents, tax manager, tax collectors, and tax accountant. Professionals in this career can also opt for teaching jobs in universities and colleges. They can also work separately as a consultant.

If for job, you are satisfying minimum percentage criterion, it doesn't really matter if you have cleared a few courses with grace marks.

Hi,
It is advisable to you to get enrolled in any of the distance university and pursue your further studies. Please find the link below for the recognised university. https://www.shiksha.com/humanities-social-sciences/articles/ugc-approved-distance-education-courses-universities-blogId-13904.