It's diplomatic...not "diplomate" (which, if you were wondering, is the term used for a person who has a diploma granted by a professional body).
The British diplomatic post in India would be the British High Commission
http://www.britishhighcommission.gov.uk ... 7170902251
The role that the British High Commission plays
http://www.britishhighcommission.gov.uk ... 2496895176
With regards to the HSMP process, my guess is that they would be the people that contact your employer, to verify your employment, verify you were at the uni you claimed you were at...hey i don't know ... probably verify your existence.
You haven't given a lot of information about your situation apart from rant that your application was refused. What sort of university did you go to (is it a recognised or random one), type of employment (the type of your company - large multinational, corner shop??) what docs did you send, where they original? Without knowing the details...all that this is, is speculation!!!!!
And I'm not even going to answer the question about how they are related to the British government because if you can't work that out...sunshine, you shouldn't be here
*sigh* i must be really really bored...