I saw a little leak from the rear axle i dont know if its coming for the hole or its coming from the transmission seal.
this is something serious? But the way what is that hole? This is after cleaning. Before its worse little worse
The leak looks like it is coming from the weep hole. This means that the axle seal is worn out.
Make sure the transmission/gear oil is not overfilled (190mL capacity at changes). The rubber vent tube to the back of the airbox should also be checked to be unclogged. Both these things can increase pressure in the transmission (when hot) and force oil out through the seals.
My 300i and 350i both had the same issue but I simply change the oil every 5,000km as in the manual so the oil level is maintained. No issues ever.
If you want to replace the seal you need to remove the rear clutch bell as the cover plate is behind it.