How much time average embassy take to mail back passport after i-730 (V92) interview?why embassy keep passport?

This is duplicate question. As indicated by my colleagues, it can take several weeks depending on the location. Please be patient.

How much longer should I wait to get my passport back or hear from the embassy?

I would contact the embassy to do a status check. Otherwise at this point , you have to wait for the decision.

Iam GC holder.Can my niece come to US from India,on student visa and study in high school here?Can we b her legal guardian here?

It really depends on the school. Ask them whether they accept foreign student etc.

Can i travel on AP after case approved for AOS since wont be able to receive the GC before travel date?

I would get the passport stamped and then travel.

Am i eligible to raise new H1B in the non exempt category.

I would set up a consultation with an employment based immigration attorney.

Would I be able to travel on a plane to Hawaii with just a work permit? And I have an Indiana I.D

I would take your unexpired valid passport with you as well.

How long will it take for my mother to be scheduled an interview after the visa fee is paid?

It will take several week. Patience is key.

What are the steps for a minor to renew a visa? Will the minor have to take new pictures, etc...?

We need more information. What type of visa is this?

I want to start consultation for yoga program based in India , one of my friend is having yoga institute in India

Please see http://www.uscis.gov/working-united-states/temporary-workers/employment-authorization-certain-h-4-dependent-spouses. "Employment...

The company wanting to hire you should have their immigration attorney review your questions. also see...