What’s the process to sponsor a family member from Mexico and bring them temporary to the U.S.? Would this be possible?

Has his grand-daughter tried to get a tourist visa?

I 130 got denied after interview ?

An attorney needs to review the documents. Normally it is faster/better for a spouse's papers than a sibling's papers.

Is it legal to stay in US after extension filed but without a receipt number?

Although this should be OK ... have you talked to the lawyer that filed the I-129H?

I agree with Mr. Smith, you don't appear eligible for a TN. Perhaps another J is possible.

Will I have an out of status period if I don't go to H4 biometric appointment if while waiting for H4 I had COS to H1b approved?

Although I think you will be OK, I am interested in learning what the employer's lawyer told you.

Q: 1) In my situation, am I able to change to Category F1? A: Yes, your mother, or her lawyer ... not you ... can change the category. Q: 2)...

If approved for 1-October-2021 you might not need to leave the US. Work with the company's immigration lawyer.

How can i start the process of becoming leagal after overstaying my visa 10 years ago?

Merely being in the US for a long time doesn't qualify you for becoming 'legal'. Have a private Skype consultation with an attorney.

Do I have any option to skip filing H1B extension once I get my Biometrics done?

You forgot to tell us the basis for you having filed the I-485. I'm going to assume it is employment based ... thus, there should be an...

L1-b visa valid till 2023, but PED was 08/2021. so the extension can be done here only without going out of USA?

Although you didn't mention it, I suspect that you're on a blanket L-1B. Thus, you need to talk to the company's immigration lawyer.