Yes. nunc pro tunc. I did.

@T S can you put me through how did you do it I will appreciate if you can explain further thank you

theres no specific format for a nunc pro tunc. you just request the Uscis to forgive you for applying late [should not be more than 180 days since your visa expired]. in my case, I had provided medical records indicating why I was late in filing.

@T S I still have valid visa, I mean the 6 month stamp on my b1/b2 has expired

get a B1/B2 extension instead then. very common to get an approval on the extension.

it taking 4 months to get a decision from the Uscis for B1/B2 extension nowadays. For O-1, without a premium processing, it will take 7+ months.