From Wiki - NBA Playoffs (http://en.wikipedia.org/wiki/NBA_Playoffs):
In the event two or more teams are tied in the standings, a series of tiebreakers are applied to determine which team receives the higher seeding.
Two-Team Tiebreaker:
- Division winner (this criterion is applied regardless of whether the tied teams are in the same division)
- Better record in head-to-head games
- Higher winning percentage within division (if teams are in the same division)
- Higher winning percentage in conference games
- Higher winning percentage against playoff teams in own conference (including tied teams)
- Higher winning percentage against playoff teams in opposite conference (including tied teams)
Three-Team Tiebreaker:
- Division winner (this criterion is applied regardless of whether the tied teams are in the same division)
- Best head-to-head winning percentage among all teams tied
- Highest winning percentage within division (if all tied teams are in the same division)
- Highest winning percentage in conference games
- Highest winning percentage against playoff teams in own conference (including tied teams)
- Highest point differential between points scored and points allowed