I had asked about whether there is any ambivalence or any anxiety or depression associated with the situation and have not heard back. If he is having any of these issues, then counseling would be appropriate and there also can be consideration of medicines to help with the anxiety or depression.
However, if the sole question is whether there is a treatment for the fact that he is gay, then as I said above, being gay, by itself, is not a medical or psychological condition, so there is no treatment for it. It is worth noting that there are some people that claim to be able to treat someone for homosexuality, via a method called conversion therapy and other names. However, this therapy has been discredited and the major professional psychiatric and psychological groups have said that this therapy has not been shown to work and is potentially harmful, so is recommended that such therapy should be avoided.
Certainly, if he is having any ambivalence or other psychological difficulty associated with the situation, it would be appropriate for him to seek therapy, but there is no need for consideration of treatment if none of these issues are present.
If I can provide any additional information, please let me know.