Serious question folks..

Seen footage at times of made guys greeting each other and there is a kiss on the cheek.

Does the guy who holds the higher rank kiss the guy, or is it the guy with the lower rank who kisses out of respect?

I know it may not happen so much now due to times changing, but I always wondered about that.

I know it may seem a silly question

It it not a "mafia" thing per se, nor did the Italian underworld develop it. Men "Kissing" one another on the cheek when initially greeting one another or saying goodbye is a very European thing, and an age-old Italian custom that was naturally carried over to many American-born Italians regardless of their vocation, or station, in life. The French and Greeks are also known for this, and several other cultures as well I'd imagine.

Thanks, being British it's just not something we do.
But I did wonder if it was a hierarchy type thing

You're welcome British.

A kiss on the cheek is popular in many densely Catholic countries. While the practice is also commonplace in parts of the Middle East and Asia, Latin America and continental Europe.

In his podcast, John Pennisi told a story about when he was at a dinner party with a bunch of other Lucchese made guys and their families.

He was at a table with a couple of Lucchese soldiers and a Lucchese capo named Jospeh "Joe Cafe" Desena came over to say hello. Pennisi and another soldier immediately got up and went to kiss Joe Cafe as a sign of respect but the other lucchese soldier was busy talking to someone so instead of getting up, he just sat still and raised his hand to greet him.

Joe Cafe didn't say anything on the spot but he later complained to the guy's capo that it was disrepectful and that the guy should have said hello the right way. According to LCN protocol, the lower ranked guy is supposed to kiss the higher ranked guy.

THAT is correct also. Lower ranking members are "obligated" to approach and say hello to higher ranking members. NOT the other way around. Its called showing the proper "respect" for the position. (Not so much to the guy himself, but for the position he holds within the family). VERY, very commonplace (and expected).