After surah Fatiha in prayer, it is wajib to recite surahs in the order of the Qur’an. For example;
It is makruh (disliked) for an individual to recite an extra surah in the second rakah which comes “before” the surah you recite in the first rakah. And reciting an ayah and then another ayah which comes before this one is also makruh. (Fatawa-i Hindiya)
For example; you have read surah tabbat in the first rakah, then in the second rakah you may not recite surah Fil or surah Maun or any other surah coming before surah tabbat. You may only recite a surah coming after tabbat such as surah Ikhlas, Falaq or Nas. Or for example; reciting surah Fil in the second rakah after you recite surah Kawthar in the first rakah is makruh (disliked), thus an individual must observe the order of the surahs.