Maximum stay on B2 Visa

[supernova5271]

My mom has a valid B2 visa and she has traveled to the US twice before. I will be in the US on H1 visa for work and she will be traveling with me on her B2 visa. My question is what is the maximum amount of time at a stretch she can stay on B2. I read online that the maximum stay is 6 month (depending on the office at port of entry). However, it was also mentioned that once in the US one can file an extension of stay. Is it possible for my mom to stay for a year during her travel without needing to go back to India? If she gets 6 months at the port of entry can she still apply for extension of stay and get another 6 months?

Thanks,
SN

[immihelp]

B2 visa is not a dependent visa for your mother to stay here all the time.

Read

https://www.immihelp.com/visa-stamp-vs-authorized-stay-duration-in-usa/

https://www.immihelp.com/frequent-visits-excessive-stay-us-visitors-visa/