hey people out there , my question is , most of the time I am able to solve problem A in most of the DIV2 and DIV3 rounds but not able to solve B problem how can I upskill myself in order to solve more then one problem I am currently doing 900 and 1000 rated problem from last couple of days what should I learn and do for solving B problem in DIV2 .

You don't have to learn anything in particular to solve Div. 2 B, just practice more and maybe a little bit harder problems.

like can u suggest me range in which i should be solving question?

1000/1100

50 random mediums on leetcode

i have more then 50 medium on leetcode random

div2B is almost equal to leetcode medium, if you cant solve B in ~1.5 hours try to set a timer when pratice maybe it helps

when you able to solve medium in ~40 min in average, you should be able to solve B in contest time

do more virtual participations and consistently solve B and C problems. Also make sure to upsolve one or two problems after a contest.

i upsolve one problem after the contest

Div2 B problem often Math/Greedy/Implemtation. Then you should try to practice that type of topic more :)

Read this pdf from Masataka Yoneda .