Procedure to appear for H1B interview with Spouse

For Mumbai Consulate

I got my petition approved and want to appear for H1B interview. If my visa got approved then my wife and my 4 months baby would require to get H4 to come with me.

My question

As my son is under 7 year and hence he exempted from interview process. I and my wife need to appear for interview. I want to go for H1 and H4 visa stamping at same time. May i know the procedure to take appointment for H1 and H4 visa date at same time?