If i doubt that i have given one sujod after completing the salah what should i do?

Answer:

If you doubt after completing your salah (i.e., after saying the final salam) whether you performed one sajdah (prostration) less in a rak‘ah, the ruling in the Hanafi school is as follows:

1. General Principle:
Doubt that occurs after the completion of salah (post-salam) is generally disregarded. The prayer is considered valid, and no action is required. This is based on the principle that once the prayer is concluded, it is presumed to have been performed correctly unless one is absolutely certain of a mistake.

In Radd al-Muhtar (Ibn ‘Abidin), it is stated: "If doubt arises after the salam, it is not considered, because the prayer has ended and its rulings have been finalized." (Radd al-Muhtar 1/543, Bab al-Shakk)

Similarly, Fatawa Hindiyya (Fatawa Alamgiri) mentions: "If after completing the prayer one doubts whether he performed one sajdah or two in a rak‘ah, his prayer is valid and he does not need to do anything." (Fatawa Hindiyya 1/132)

2. Exception – When Certainty Overtakes Doubt:
If the doubt later becomes certainty (i.e., you become 100% sure that you missed a sajdah), then the prayer is invalid and must be repeated. Mere suspicion or probability does not invalidate it.

Imdad al-Fatawa (Mufti Muhammad Shafi‘) states: "If after the salam one is certain that a fard (obligatory act) was omitted, the prayer is not valid and must be repeated. But if it is only a doubt, the prayer is correct." (Imdad al-Fatawa 1/118)

3. What if the doubt occurred during the prayer?
If the doubt about a sajdah occurs before the salam (while still in the prayer), the rules of shakk (doubt) apply. In such a case, the person should act upon the lesser number (i.e., assume the sajdah was not performed) and perform sajdah sahw at the end. However, since your question specifies "after completing the salah," the above ruling applies.

4. Practical Advice:

• Ignore the doubt and do not repeat the prayer.
• If you repeatedly suffer from such doubts (waswasah/obsessive doubts), it is best to ignore them altogether and not act upon them, as per the guidance of the fuqaha.
• If you later become absolutely certain (e.g., you clearly remember not performing the second sajdah in a rak‘ah), then you must repeat that salah.

5. Summary Table:

| Situation | Ruling | |-----------|--------| | Doubt after salam (not certain) | Prayer valid; no action needed. | | Certainty after salam (100% sure) | Prayer invalid; repeat it. | | Doubt during salah | Act on lesser assumption, perform sajdah sahw. |

References from Hanafi Books:

• Radd al-Muhtar (1/543, Bab al-Shakk)
• Fatawa Hindiyya (1/132)
• Imdad al-Fatawa (1/118)
• Fatawa Usmani (by Mufti Taqi Usmani, Vol. 1, p. 478)
• Bahishti Zewar (by Maulana Ashraf Ali Thanwi, Section on Doubts)

Conclusion:
In your case, since you only doubt after completing the salah, your prayer is valid. You should not do anything extra (no repetition, no sujood sahw). Simply ignore the doubt and continue with your regular acts of worship.