There are many options to watch the NBA while cutting cable and satellite but you will not be able to watch the Houston Rockets games. Locally they are televised on Root Sports but that channel is only available on DirecTV, AT&T U-Verse, and Comcast. Here is how to watch all the other games on your TV.
The nationally televised games are on ESPN, TNT, and ABC.
ABC games are available free over-the-air with an antenna connected to your TV.
For the next options you will need either a Roku, Amazon Fire TV, Google Chromecast or Xbox One.
ESPN and TNT games are available with Sling TV ($20 a month)
ESPN and ABC games are also available on the WatchESPN (ABC games you don't need a login but ESPN you do, you can use the Sling TV login)
If you follow another team other then the Houston Rockets you can get NBA League Pass for that one team for $60 and you can watch with the NBA Game Time app. The NBA Game Time app is available on Roku, Amazon Fire TV, Google Chromecast, Apple TV, Xbox 360, Xbox One, PS3, and PS4.
If you want to watch all the teams except for the Rockets you can get NBA League Pass for $100 and watch using NBA Game Time app.