My question is that one night I had ihtilam and I realized this after I had offered Fajr namaz. Would my namaz be accepted as this happened by mistake? Please answer it soon.
بسم الله الرحمن الرحيم
(Fatwa: 433/B-89/TB=03/1435)
If you found it after offering Fajr salah then your salah was not valid. Hence it is necessary to reoffer it after making ghusl. It is mentioned in Dur al-Mukhtar:
وجد في ثوبه منياً أو بولاً أو دماً أعاد من آخر احتلام وبول ورعاف ٍ (الدر المختار ج 1 ص 40 دارالكتاب)
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband