Actually Giovanni gives out TM26 Earthquake. He gives it to the player as a prize after you defeat him in a Gym Battle to win your 8th Badge in Pokémon Fire Red and Leaf Green. TM27 which is actually Return in this Generation can be found on Route 12. Fissure lost it's status as a TM in Gen II.
In Pokémon Red, Blue and Yellow Giovanni gives out TM27 (which was Fissure in this Generation), as a prize when you defeat him in a Gym Battle for your 8th Badge. TM26 Earthquake can be found in Silph Co. on the 10th Floor in Pokémon Red, Blue and Yellow.
Hope I helped :)