ydwivedi:
1. how long it may take on fresh filing of I-824?
Answer: 5 minutes of paperwork and abuot 3-4 weeks to get I-824 receipt!
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2. NVS and other processing time.
Answer: I think you mean NVC National Visa Center which does admin work for regular CP. In your case, you will haev to do what is called AC I-140 where it bypasses NVC and your attorneys can approach the consulate directly based on I-824 receipts and AC I-140 packet. Read this link for details on AC I-140 process:
http://www.immihelp.com/gc/consular/ac140.html
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3. How long it may take to get a date with New Delhi CP?
Answer: Filing and receving I-824 receipt = 1 month. Filing AC I-140 application with I-824 receipt and getting interview = 4 months. SO total 5 months assuming you have streamlined your AC I-140 process and attorneys agree with AC I-140. This process you cannot do without attorneys hence the name Attorney Certified I-140.
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4. Would it be safer even to start CP (knowing that my I-485 is
already in process).
Answer: In your case it would be AC i-140, a type of CP not the regular CP. CP/ AC I-140 is safe is your job is stable until your cp interview date, no criminal background in any country after age of 16, never been out-of-status and no medical contagious history from past/ present. This is true for all dependents on your case too.
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5. Would I be saving on time...benefitted by CP process with above facts.
Answer: With AC I-140/ CP you will be done in 5 or atmost 6 months whereas 485 you know well what that means!