What are the tournament categories to get a ranking?
The USTA rules:
Tournament Categories: Each year the USTA holds four (4) Category I National Championships in each age division on different surfaces: hard; grass; clay; and indoor (hard) courts. There are numerous Category II National Championships which are also held each year on various surfaces. In addition, each section holds various sectional tournaments (sometimes also referred to as “designated” or “closed” tournaments. Check with your section office to find out which age division tournaments are sanctioned as sectional championships (2x) and which are sanctioned as local (1x) events.
Minimum Ranking Requirement: To be eligible for a national ranking in singles or doubles, a player must play in one (1) Category I National Championship in the age division in which the player seeks to obtain a ranking.