What is the ruling on one who prays some congregational prayers in the mosque and some at home due to being busy, or the mosque being far, or being in different places at the time of the call to prayer?

Men must perform the obligatory prayers in congregation in the mosque, whether the mosque is adjacent to the home, the market, or the workplace. It is not permissible for a Muslim to perform the obligatory prayers in his home or workplace except for a valid excuse. Whoever prays them elsewhere than the mosque without a valid excuse has abandoned an obligation, and is sinful for abandoning it.