Tyga -- Lost $70k But Still Fighting for Crib in Kylie Jenner's 'Hood

Tyga needs to just move in with Kylie Jenner already, because he's been ordered to fork over $70,000 in back rent on a house in her gated community -- a pad he claims he's actually buying.

Tyga's gone to war over the Calabasas home -- just a few minutes from Kylie's -- and on Monday a judge ruled he had stiffed the landlord. Even with $70k on the line, Tyga didn't even bother showing up in court ... possibly because he says he's no renter.

Last week he filed suit against the landlord, saying he has an agreement to buy the property, and even plunked down $200,000 as a down payment. Until that's settled, the bottom line is ... he's gotta pay up AND move out.

The good news -- as of 2 weeks ago he can bunk up with KJ. Legally.