kayo and espn is your best bet - you can get a ACC or SEC Pass, but Kayo showed most of the tournament. And if you don't mind watching delayed games you can access a lot fo college hoops for free online via Stadium Sports.

Depends if you're just a Div1 guy or you sit in the hipster category of watching Div 2 & 3

There isn't.

Each major sports network and conference in the US has its own network and streaming service.

The only centrally administered stream by the NCAA is for the tournament.

In Australia a paid Foxtel subscription allows you to watch the primary plus streamed-only-in-Australia secondary channels (ESPNU, ESPNNews, SEC Network, ACC Network) and overflow games on WatchESPN (AU version). They cover a lot but not everything.

Also 7plus streams PAC12 Network into Australia for free.

Otherwise you'd have to go down the VPN route and buy a US pay TV login to access every network's streaming service that airs NCAA - ESPN, FSN, CBSSN, NBCSN and each major conference network.

Just to back up on what Perthworld posted, if you get a USA/VPN modem and subscribe to one of their pay TV online products with a sports package, an extra $5:00 I think it still is will get you ESPN+.

With ESPN+ you get access to almost all D1 college basketball and other sports who recently joined this new off shoot of ESPN, not ESPN but known as ESPN+.

The Roku device is very good and will allow you to connect using the modem and access a US based account for their pay TV, if it is set up correctly...

It also depends on what the OP wants - to follow a specific team, a specific conference or just the bigger games in general.

If you go down the VPN route here are the major broadcasters and their respective sports networks in the US:

ABC/ESPN https://en.wikipedia.org/wiki/List_of_ESPN_sports_properties#Basketball
CBS/CBSSN https://en.wikipedia.org/wiki/CBS_Sports_Network#College_sports
FOX/FS1 https://en.wikipedia.org/wiki/Fox_Sports_1#Programming
NBC/NBCSN https://en.wikipedia.org/wiki/NBCSN#College_sports

Over the top service/additional coverage:

DAZN https://en.wikipedia.org/wiki/DAZN#Sports_rights (no college basketball airing on the US version at the moment)
ESPN+ https://en.wikipedia.org/wiki/ESPN%2B#Programming

Big5 conference networks (note: Big 12 does not have their own channel (yet))

https://en.wikipedia.org/wiki/ACC_Network#Programming
https://en.wikipedia.org/wiki/Big_Ten_Network#Basketball
https://en.wikipedia.org/wiki/Pac-12_Network#Programming
https://en.wikipedia.org/wiki/SEC_Network#Programming

Schools lower than the Big5 and middle tier = local TV/syndication/some of the above.

It really is a minefield.

VPN like they said above can get one for 1.99 a month for 5 years or you just troll Redditt for individual games

NCAA hoops is the main reason I have kept my Foxtel subscription. Mainly it's the P5 conference games with the odd Saint Mary's game thrown in. To watch the SMC games I stream on theWtv.com which is really good quality. Come tourney time, Foxtel pays for itself in my house!

I failed to mention above, my Foxtel subscription also gives me access to watchespn.com which has some games that aren't shown on ESPN or ESPN2 which is also an added little bonus.