Sec 292A

Section 292A is not applicable to Private limited Company as first few introductory words of section itself clearly states that Every public limited Company having paid up capital of not less than five crores rupees shall constitute a committee of the Board known as "Audit Committee"

which means it is not applicable for private Co. regarding your second doubt ,generally many section which are applicable to pvt. co. which are subsidiaries of public co. section specificaly mentions regarding such applicability but as this section does not specificaly mention this ,we can assume that it is not applicable to  private companies which are subsidiaries of public companies   

its is applicable to all public cos having  paid-up capital of not less than five crores of rupees.

not applicable to private co. & pvt . co. which is subsidiary of public co.

hi
 

i agreee with the answer of arpita

Hardik