Sugges me that chemical engineering is good option or not and what is disadvantage when i pic it

It is a subjective question and its answer depend on how you describe " good ". If you are taking jobs into consideration then also chemical engineering is good. As it provides good jobs across the country and if you are really interested in chemical engineering don't just think too much and just follow your dreams.

For getting more information regarding carrer opportunities refer here

https://www.careers360.com/question-what-are-scopes-in-chemical-engineering-for-better-job-opportunities

Chemical Engineering is a very good field, good career prospects.

If you are a process engineer you are like a hot cake. There are many chemical companies especially petroleum companies that have deficiency of well experienced chemical engineers. If you get the designation of process engineer the career options are endless or you can assume managerial roles……..

That said, there are cons:

Its initially very difficult to get jobs, Industry prefers experienced people, even as contract employees.

Lot depend on the college you are from, try to do chemical engineering from reputed colleges (IIT, NIT, UPES, Imp state colleges with excellent placement). Companies like BPCL, IOCL, Cairn, Reliance, Shell takes students from these colleges only. PSUs come in these colleges for placements directly (no need GATE).

The requirement of chemical engineers are low compared to electrical or mechanical engineers even in chemical companies. But this handful chemical engineers rule the plant, others works according to your wishes.

If you miss the campus opportunity it may be difficult to get job unless you are well hooked up (money, contacts, influence).

Please don’t do chemical engineering at mediocre colleges:
No core placement (you may find other placements).
Knowledge of the staffs are very limited (Learn from the best).