Question

correct the sentence my uncle is in the committee​

Answer 1

There is nothing wrong in the sentence.

Maybe this sentence would sound better :

My uncle is a part of the committee

Answer 2

There is nothing wrong in the sentence. The tradability is slightly hampered with this syntax because uncle is one of the members of the committee. The sentence will read better if it is written as “My uncle is one of the members of the committee”.

Here the status quo if the uncle as the family members will be clearly notified.