Is it permissible for someone from whom involuntary drops of urine are discharged, and who is unable to wash the place of impurity, to pray the prescribed prayers, including Friday prayer, and is he required to repeat them?

It is not permissible to delay the prayer beyond its appointed time. The conditions for its validity, such as purity and covering the 'awrah, must be prepared. If water is available or it is possible to change clothes, it is not permissible to pray before purifying oneself from impurity. This is because purity is a condition for the validity of prayer. Whoever prays with impurity, knowing about it and being able to remove it, their prayer is invalid and they must repeat it. This includes the Friday prayer, which must be repeated as a Dhuhr prayer.