I cannot root or access developer options My Samsung Galaxy Tab A (model number SM-P550 if you want to know the specs, Android version 6.0.1) will not allow me to "unhide" or "unlock" my developer options no matter how many times i tap the build number. On another note i am unable to root my device and because i do not currently own a pc and i have tried every mobile rooting technique i could find, thank you for adressing this issue.
Edit - so i finnally figured it out, this device has many "accounts" and you can only access thing like the dev options on the "owner" but i was using "guest" but i still cannot root but im sure i will figure it out eventually, thank all of you for your suggestions and help!
Every Android should be able to get developer options.  Wrichik Basu's comment says how to show developer options. However OEM Unlocking (first step to root) is disabled on basically all Samsung phones.