[wmirkru]

I read it in Aap ke Masail aur un ka hal that if u happen to recite Surah Naas in first rakah than u have to recite it in all 4 rakahs and Allah ta'ala knows best.

there is a difference of opinion in hanafi madhab on this; some say decending order is wajib, but others say it is not wajib but only reccomended...; both these opinions are deobandi

thus according to the latter opinion, one dont literally have to say the surahs in order for salaah to be valid

this however only applies to fardh salaah's...; in sunnah or nafl salaah, surahs can be said in any order at all