Russia has a strong military and should be able to retaliate if they desire.
There are lots of people who would be thrilled for Russia to take ISIS out. However there are probably just as many people who would be afraid of a scenario where Russia defeats ISIS and gains a stronghold in the Middle East.
He who controls the oil controls the world.
Having said that if it had been a U.S. passenger plane bombed by ISIS Americans would expect our country to put boots on the ground in an all out war to avenge the attack.
Russia has the right to do the same.