Diploma

Yes, you can get it from the admin cell. You have to present the documents that you have passed from this college.

Hi,
It is great that you want to study more. Kindly, specify your qualification so that I can help you with good options else MBA is a great option.

Hi,
Kindly, refer to the list below, change the filter option as per your preference:
https://it.shiksha.com/computer-programming-language-courses-in-india-categorypage-10-105-1-0-0-1-1-2-none-1-0?

No it is not recognised as a diploma so you cannot do any higher education using that qualification

Govt. polytechnic, Visakhapatnam is the best for Diploma in mechanical engineering.

AMIE is recognised equivalent to engineering graduation degree by the government and you will face no problem in government, PSU, armed forces and paramilitary forces jobs because of AMIE degree. You may face minor challenges in the private sector, but with the right experience, you will able to overcome all the challenges. Career growth will be better as per your performance and experience not because of your degree.

Please mention your academic and work profile, your stream of interest etc. It is not possible to answer this question without knowing your profile.