US Immigration from India

Hello, this question is for my cousin who recently applied for tourist (B2) visa at Mumbai consulate in India. When he got his passport back he noticed that he only got single entry with 3 month visa validity (US visa expires in June). The thing is that he was not planning to travel until later this year as he has commitments in India in June (medical clearance exams, pending covid vaccine etc). What are his options at this point? If he doesn't come to US on this visa before June, is he eligible to apply again or renew it? How will that application go (what are his chances of approval or renewal at that point?)? I want to know if someone was in similar situation and can offer any inputs. Thank you for your help in advance.

I tried to see if there were any similar previous threads about this, but wasn't finding anything. Our I-129F was recently approved, and I received the NOA2 in the mail. (I am the U.S. citizen petitioner, living in the U.S.) However, I moved to new address about a week ago. I guess I have two questions: Do I need to update my address with USCIS still? And do I need to update my address with the NVC? I know how to update my address with USCIS, but I'm not clear on how to do so with the NVC, so if it's necessary, I'd appreciate if someone could give advice on that. Thanks!

My husband came to USA on a K1 visa and we were married in California, USA. I want to apply for my OCI since we have been married for 2 years and it says "apostilled marriage certificate" required. Does that mean I get it apostilled here in California for India? I was also reading about the Apostille Convention and am a little confused, does it mean it's required to apostille it but it's still valid in all the other countries part of the convention?

I just had a baby recently and my interview is on April 7th. I do not intend to send my child to a baby sitter, so do i need to call to have them make an accommodation for us? OR do we just show up to the interview with her? Any suggestions are welcome..

Side questions

Can you bring diaper bags/backpack and stroller?

Thank you!

Last week, I got our NOA2 in the mail (approved, happily). My middle named was misspelled on it. It wasn't a major misspelling, I guess, in that they got one vowel wrong. But it doesn't precisely match what's on all my documents. (Needless to say, I went back and looked at the I-129F I submitted, and I spelled my middle name correctly.) Does anyone know the best way to go about correcting something like this? If it's helpful to know, I'm the US citizen petitioner.