Student visa refusal

[vinny]

It’s difficult to advise with incomplete or misleading information.

What are the course details that’s written on the College’s official letter?
How old is your cousin?

[dylecck]

It’s difficult to advise with incomplete or misleading information.

What are the course details that’s written on the College’s official letter?
How old is your cousin?

The course is General English and 23 years old.

[AmazonianX]

It’s difficult to advise with incomplete or misleading information.

What are the course details that’s written on the College’s official letter?
How old is your cousin?

The course is General English and 23 years old.

What are the course details??? You can not be presenting incomplete details and expect a fill correct response on the information you are providing!
If the course is 6months +1week, how will applying for 6months visitor visa help on completing the course? Hypothetically your cousin knowingly wants to become an overstayer to complete the course or there is no intention to leave UK after the course? The father is in UK, father's employer providing some backing ....., is the applicant a genuine visitor?
You need to think how the CW will assess the application.
You were earlier told which application suits and will be appropriate. Don't let his travel history become jeopardised.