Where is Giovanni in soulsilver?

Giovanni is found in the Kanto region, specifically in the Viridian City Gym. However, to find him there, you must first complete the following steps:

1. Defeat the Elite Four and Champion in Johto.

2. Travel to the Kanto region.

3. Go to Viridian City and enter the gym.

Once inside the Viridian City Gym, you'll find Giovanni waiting for you at the end.