How our child above 21 year old come with us on my immigrants visa of usa ?
It would depend on what sort of immigrant visa you are applying for. If you’re talking about an IR-5 parent of a US citizen, it wouldn’t be possible. If you’re talking about some sort of family preference category, it might be possible depending on a variety of factors under the provisions of the Child Status Protection Act and you should talk to the embassy immigrant visa officer to see if this would apply for your child or not. If this child is married though, it definitely wouldn’t apply. If your child can’t be covered on your immigrant petition, you would have to file for him after you arrived in the US, but that would take a number of years.