Question

I am 6 letters word indicates part of the Human body 1,2,3 are used to call the children age between 1-6 or 7 and 1,5,6 are used for the house before entering . 6 th letter indicates to question

Answer 1

kidney
hope this helps

Answer 2

yeah it's KIDNEY.
1,2,3 : KID: Children between age 1-6
1,5,6:. KEY: use before entering the house