Query

You can write in following manner:
"As per the provisions contained in section 139 of the Companies Act,2013" or "Provisions of section 139 of Companies Act, 2013 states that..."
Even if you don't know the section no. then don't worry, you can write answer as- " As per the provisions of Companies Act,2013..."

Quote the numbers of  subsections or clauses only when you are sure. If you quote wrong sections , you will lose your marks. So, it's better not to quote in case you don't remember exactly.

And I agree with the way Mr.Harshal asked you to write the answers.