The 26-year-old has been chased by the Primera Liga champions for most of the summer and a deal appears imminent.
Spurs chairman Daniel Levy had steadfastly refused to sell the Croatia international unless their valuation is met.
Levy turned down a reported £40million bid last summer from Chelsea, who had elevated the playmaker to their number one target.
It appears Tottenham will now accept a reduced fee for the former Dinamo Zagreb starlet who seems intent on leaving White Hart Lane.
“You read many things in the media but from the information that I have, Luka will move to Real Madrid for sure,” Mamic told 24sata.
“I’ve heard it’s almost done, so I don’t have any doubts Luka will play for Real Madrid next season.
“It is just a question of when the official announcement will be.”