@mitdesai21
You don't have a correct understanding of the situation, at least not as you've expressed it in your post.
"So at the end the gains/loss is eventually calculated based on the corrected value and not the actual cost basis. Right?"
No. At the end the gain/loss is calculated based on the corrected value which is the actual cost basis. It's not calculated based on the erroneous cost basis (typically "$0") shown on the 1099-B.
"Lets say (an) RSU vested...and the stock price was $10 on vest. Sold it at $11 on the next day. The cost basis (reported by the broker) will be 0. But the Adjusted Cost basis will be $11 indicating that I had $1 short-term gain."
No, the Adjusted cost basis will be $10, giving you a $1 short term gain.
"So when filling out the details in TT, I will have cost basis at 0 and on the next page, the adjusted cost basis will be $11. "
You'll enter the 1099-B exactly as it reads, showing a $0 basis. Then on the next page you enter the correct "adjusted" basis to $10.
I think you actually do understand what's going on here, but just expressed it incorrectly.
Just to be clear, you'll enter the 1099-B exactly as it reads, incorrect "$0" basis and all, and then correct the cost basis on the next page.
