A brief description of ranks in the senate can be found here. Do not confuse your senate rank with your characters rank in the Kirin Tor, they are two separate things.
The OOC rank is reserved for alts of already existing members. The Magus Senate only takes pure OOC members in rare cases. The citizen rank is for alts and people who are IC but not members of the Senate as a legislative body. Citizens may become sitting members of the Senate but will have to advance in the ranks starting at junior senator regardless of how long they have been a citizen.
This is the beginning rank for all sitting members of the Senate. Junior-Senators get full voting rights. The Junior-Senator rank is also the trial rank for new members.
This rank means you have been in the guild for a while and have been active. Perhaps you have hosted an event or two. You participate in RP outside of official events.
You are a trusted member. You have been with us for a long time and you participate in a wide range of guild activities. This is the highest rank that non-magi can attain.
Magus is the veteran rank. This is the last rank that comes with no OOC guild authority.
This rank is for those who contribute to the guild in a big way either through IC or OOC actions such as hosting events, recruiting, website/wikia work, helping new members, etc. Former officers and other trusted and long standing members are also at this rank.
These people are the officers of the guild. They head up the ministries IC. Contact these people if you have issues.