Hi Rachit! 

Yes eudiometry is important for jee main as 1 question is asked every year since last 3 years.

So you should practice eudiometry questions.

Listen, if you have paucity of time then you can skip it for jee mains. But if you have no such issue of time then it is to better to be on the safe side and do it.

Because jee papers are unpredictable,doesn't follow certain pattern, and the difficulty is boosted a bit owing to its unpredictability.

Best of luck for jee 2020

Please upvote if it helps.

Eudiometry is a toipc of physical chemistry and generally taught under gaseous state.

It is an imp. topic according to various coaching institutes. Also in gaseous state, eudiometry covers a major part apart from ideal gas eqn. and real gas eqn. So I suggest you to solve a good number of problems as at least one question is found from this toipc almost every year.