sayın bay bayan yaklaşık altı yıldır size ev başvurusu yapmış bulunmaktayım.Ama bir sonuç alamadım.Doktor raporu olmasına rağmen ve geçerli şartlar olmasına rağmen niye bir sonuç vermediğinizi bilmiyorum.Beni bu konuda aydınlatirsanız sevinirim.Saygılar
It has been been six years since I submitted a home application to you. I don't know why you haven't reached a decision in spite of the fact that a doctor's report and the required conditions were provided. I would appreciate it if you would shed some light on this matter for me. With respect,
Oh, just for being a conditional sentence, I think it should read conditional +if+ past.
Either
"I would appreciate it if you shed some light on this matter for me." or
"I would appreciate it if you could shed some light on this matter for me."
I'm sorry if I misunderstood the line.
Also there are two "been" in the first line.
Actually, I was guessing you were following that rule, and to be honest, I don't know why this one doesn't follow that rule, but I think it's because the word "would" here has a somewhat different meaning: "be willing to".