All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If you join the prayer with the Imaam at any Rak'ah while he is standing and before he bows down, then you should recite Al-Faatihah (chapter one), because according to the preponderant opinion of the scholars a person led in prayer is required to recite Al-Faatihah as the Prophet said to his companions: “It seems that you are reciting the Quran while being led by an Imaam? They replied: “Yes.” Thereupon, the Prophet said: “Do not do so except Al-Faatihah as there is no prayer [the prayer of a person is not accepted] for whoever does not recite it.” [Ahmad and Abu Daawood]. For more benefit, please refer to Fatwa 81333.
Nonetheless, if a person does not recite Al-Faatihah acting according to the view of the majority of the scholars then his prayer is correct and he is not obliged to make up one Rak'ah if he misses the recitation of Al-Faatihah by the Imaam. Similarly, the person led in prayer who is not able to recite Al-Faatihah or if he recites it, he misses the Rukoo' (bowing down) with the Imaam, then he should bow down with the Imaam and count it as one Rak'ah and he is not required to do anything else [his Rak'ah is correct and acceptable and he does not have to make it up].