SUPPLICATION (DUA) AFTER NAMAAZ
It is indeed a blessing, and beneficial to make dua particularly, after Namaaz, as a means to supplicate in the court of Allah Ta'ala that the Namaaz we performed be accepted.
Allah Ta'ala states in The Holy Quran:
'So when you are free after prayer, then strive hard in invocation'
'And attend to your Lord alone'
(Surah Alam-Nashra. verse 7,8)