16 and 17 is good for supporting doc.
there are the question bank that u may wanna go through.just a basic hint that might be asked.
QUESTION BANK FOR INTERVIEW AT US EMBASSY/ CONSULATES
Q1. Which Company are you going to work for in the united states?
Q2. Where is the Company located?
Q3. How did you know about this company?
Q4. What job has been assigned to your by cerebra consulting?
Q5. What are your technical expertises in the field you are going to work in US?
Q6. Where are you presently working?
Q7. Can you tell me some thing about your present company? What kind of development work are you undertaking?
Q8. What are your educational qualifications?
Q9. Have you ever been to the USA?
.
Q10. Do you wish to settle down in US?
Q11.Do you have any parents or relatives here in USA?
Good luck.