What is the ruling on delaying the Fajr prayer until 10:00 AM due to janabah and defiled clothes, and the unavailability of a place to perform ghusl or clean clothes at work? Is it permissible to pray in clothes defiled by a wet dream if ghusl has been performed, or if one is unable to perform ghusl or wash the clothes?

Semen is pure (tahir), and prayer is valid when performed in clothes stained with semen. However, it is preferable to wash it off to avoid disagreement among scholars. If you wake up in a state of major ritual impurity (junub) and perform ghusl, then pray in the clothes you slept in and had a wet dream in, your prayer is valid. It is not permissible to delay prayer due to the absence of water to wash off semen. Similarly, it is not permissible to delay prayer until a later time if you cannot find a place to perform ghusl; instead, you should perform tayammum (dry ablution) and pray, without delaying the prayer beyond its prescribed time.