Answer
(Fatwa: 1874/1438=H)
If Mumbai is your native place or you intend to stay there for 15 days or more and you enter in Mumbai at 04:40 then your journey came to an end and you became muqeem. Now, you have to offer four rakats in the above mentioned situation.
(2) It is not necessary to reach ones destination but if he enters in the city after sunset then he will do qasr and if he reached before sunset and the salah was missed then he will pry full salah.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband