One vs. One's vs. Ones'

ONE: (प्रत्येक व्यक्ति*)

#Pronoun

e.g. One should help others.

e.g. One must take care of one's family. [One's= Possessive adjective]

ONE: 

#Pronoun

e.g. This phone doesn't work so I need a new one. (..एक नया)

e.g. How was my joke?- It was a good one. (..एक अच्छा)

e.g. Does this car belong to either of these two brothers?- Yes, it is the elder one's car. (..बड़े वाले)

[one's= possessive for one person]

e.g. Whose admit cards are these?- These are the unemployed ones' admit cards. (..बिना रोज़गार वालों)

[one's= possessive for more than one person]

ONE: (एक)

#Noun

e.g. One is less than two.

e.g. One is an odd number.

ONE: (एक)

#Determiner

e.g. One boy was absent.

e.g. Only one boy came.