Kindly correct the letter

[JRD]

Sub: Request for Personal loan

This has reference to the above subject

Our staff members, Mr.X and Mr. Y have requested a personal loan in the amount of $000.00 each for their vacation expenditure.

They are willing to pay it back, within six months, from their monthly salary

I would request you to look into this matter and kindly approve the loan as requested

[wtf]

NOT A TEACHER!

It is very important to notice that different countries may have different formats for formal letters. For example, in the United States of America, in the subject line we would write:

"RE: Request for Personal Loan

In reference to the above subject, our staff members, Mr.X and Mr. Y, have requested a personal loan in the amount of $000.00, each, for their vacation expenditure.

They are willing to repay it within six months from their monthly salary.

I would request you to look into this matter and kindly approve the loan as requested."

What Da

[Anglika]

In this context, the collocation is "With reference". However, if you have a subject line, there really is no need to refer to it in the body of this kind of letter.