If a national network (TNT, NBA TV, NBCSN, etc) has an exclusive broadcast, only that national network will provide that game.
If a national network and regional sports networks are airing the same game, there may be blackouts based on where you're located.
For example, a Houston Rockets vs. Golden State Warriors game is airing on both NBA TV and each team’s regional sports network, AT&T Sportsnet Southwest and NBC Sportsnet Bay Area respectively. The game is available nationwide on NBA TV except in the Houston and San Francisco markets. The game will be available to local fans on AT&T Sportsnet Southwest and NBC Sports Network Bay Area.