@Vinod8 - If you search the community forum here, this question is asked many times. There are some nuances to explore with listing multiples, how to use the extra person fee, how to coordinate your calendars, if you want to take multiple reservations, if you want to make sure you are paid for all beds used even if there are only a few people .... take some time to read all the answers to make sure you are set up the way you want.
Short answer - you must create a separate listing for each of the scenarios of rooms and combinations you want to provide to get the right number of people and the right number of rooms for the right price.
https://www.airbnb.com/help/article/289/how-do-i-list-multiple-rooms
example:
Listing #1 - one bedroom up to 2 people - $xx
Listing #2 - two bedrooms up to 4 people - $xx
Listing #3 - three bedrooms up to 6 people - $xx