Explanation:

A person who has joined the Imaam whilst the Imaam is in Rukoo’, will be regarded as one who has performed the complete Rakaat. Once the Imaam has completed the Rukoo’ and a person then joins the Imaam, he has missed the Rakaat.

Such a person is known as Masbooq.

How should that person continue:

1. A person who has missed any Rakaat of Salaah read in Jamaat, should continue the Salaah with Jamaat till the end.
2. Once the Imaam turns to say the second Salaam, the Masbooq should stand up and complete the missed number of Rakaat.
3. If the Masbooq has missed only one Rakaat:
   1. The person should stand up
   2. Read Thana
   3. Ta’-awwuz
   4. Tasmiyyah
   5. Surah Fatihah
   6. And another Surah
   7. and thereafter complete the Salaat.
4. If the Masbooq has missed two Rakaat in Fajr, Zohar, Asr or Esha:
   1. The person should stand up
   2. and complete both the Rakaat by reciting Surah Fatiha and another Surah in both the Rakaat
5. If the Masbooq has missed two Rakaat in Maghrib Salaat, then:
   1. the person should stand up and
   2. After completing the first Rakaat make Qa’dah, read Tashahhud
   3. then stand up for the 2nd Rakaat.
   4. After reciting Surah Fatihah and another Surah
   5. complete the Salaat.
6. If 3 Rakaat where missed in Zohar, Asr, or Esha, then:
   1. the Masbooq should stand up
   2. Read Surah Fatihah and a Surah in the 1st Rakaat.
   3. Thereafter make Rukoo and Sajdah
   4. But before standing up for the second Rakaat make Qa’dah (sit down)
   5. read Tashahhud
   6. then stand up for the second Rakaat.
   7. In the second Rakaat recite Surah Fatihah and another Surah
   8. complete the second Rakaat and without sitting for Tashahhud
   9. stand up for the 3rd Rakaat read only Surah Fatihah and complete the Namaaz.
7. If a person has missed all the Rakaat of any Salaah, then he should repeat the whole Namaaz after the Imaam has said the Salaam except that he should NOT raise the hands to say Allahu-Akbar (Takbeer) in the 1st rakaat.

Note: For a person that joins the Jamaat when the Imaam is in Rukoo, it is Fardh to stand and recite the Takbeer-e-Tahreemah and thereafter to stand at least for a duration long enough in which Subhaan-Allah could be recited once then go into Rukoo.

Reciting Takbeer and going into Rukoo without pause is not permissible. Salaah performed in such a way will not be valid and should be repeated.

Note: One should not join the Jamaat after the Imaam recites the 1st Salaam to complete the Salaah.

Note: A person should not run in the Musjid to join the Jamaat if he is afraid of missing any Rakaat. It is not proper to run in the Musjid.