Hi Sohail,
In normal use there are just 2 types of Circuit breakers, Oil Immersed contact type and Air type.
1. Oil circuit breakers are high-voltage circuit breakers that have their contacts immersed in oil. The main disadvantages of oil circuit breakers is the fact that the oil can be flammable and it may be hard to keep the oil fresh and in good condition (requires changing and purifying the oil).
2. Low voltage normally use the Air type breakers, as no ARC is expected across the contacts.
There is no GAS type circuit breakers as far as the contacts are concerned.
Hope this will help.
Raza