Impossible in today world to see Real Madrid seeling a player like Rodrygo to a broken Barcelona, guys some of you seems to forget that Barcelona is BROKElona, they dont have money at all, they dont have cashflow, the problems are still there, so if Real Madrid ask for a lot of money they cant pay at all.
This issue is becoming more prevalent when we see transfer news. But I doubt this transfer. As far as I can recall, it's very rare to see a Real Madrid player sold directly to Barcelona, unless the player is first sold to another club and then bought by Barcelona.
So, Rodrygo's chances of moving to Barcelona are very slim. Furthermore, as you mentioned, Barcelona couldn't even sign Neco Williams due to financial constraints, let alone sign Rodrygo, whose salary is certainly much higher. Furthermore, I strongly believe Real Madrid will not agree to sell Rodrygo to Barcelona. It's safe to say this transfer is highly likely to fail.