ANSWER:

He must stand up immediately, perform ruku, stand up for ruku, go to offer his two prostrations and then offer the tashahud to conclude his prayer, offer Salam then offer 2 prostrations of forgetfulness and then offer another salam.  

If a person forgets to bow in the fourth rakah of obligatory prayer & remembers it in the tashadud, then should he stand again & Complete the rakah, considering it as fourth or should he finish of his prayer & again pray the whole Salah? As bowing is one of the Arkan of the salah.

Prayer |