Family visitor visa

I'm married to a british citizen and permanently settled in UK and we have a 5 year old son who is born with learning difficulties, but my 24 year old eldest son from my previous marriage who's still a student lives in India with my elderly mum and is currently visiting us here in UK to spend quality family time and bond with his younger brother. My 5 year old has become very attached to his elder brother and they have bonded so well, and it pains my heart to think that in less than a month's time my eldest will have to leave to return back to India, and he's also very sad and dishearten to think that he would have to leave soon and not see his mum, brother and stepfather for a long time, afterall we are the only family he's got apart from my elderly mum. Is there any path I could take to apply for my eldest to stay in UK and be with his brother, he's willing to work and take up any jobs available as long as he could be with his family.

I would appreciate any advice (here's a mother calling for help to be with both her kids).

Nope, not through the family route unfortunately.

Also, a person in the UK on a visitor visa is not permitted to switch to any other category of visa within the UK. Any application he might qualify for, has to be applied for from India.

The only visas he can look into to see whether he might qualify is Tier 4 Student visa (not sure if he has university behind him already) or a Tier 2 General visa for which he will need an approved sponsor and are not so easy to get.