Newspaper and communications tycoon Thohir met Inter president Massimo Moratti in Milan last week to discuss a potential 300million euros investment in the San Siro outfit, with reports in Italy suggesting he could even assume a controlling stake in the club.
Thohir returned home after positive talks but, in an interview with Indonesian magazine Republika, he admitted there was still some way to go.
Quoted in the Gazzetta dello Sport, he said: "I don't know if the deal will go through or not. I don't know, and I don't know how long it will take.
"There are other things we need to work out with Inter, but everything is going in the right direction.
"Whether I take a minority share or a majority (share) will be important; we'll see what can be agreed."
Should Thohir acquire up to 75 per cent of Moratti's shares, as is rumoured, he intends to restore the Nerazzurri to the top echelons of world football.
Inter's fortunes have dipped significantly since the treble-winning campaign of 2010, with the club finishing a dismal ninth in Serie A last season after selling stars including Wesley Sneijder and Samuel Eto'o.
"The goal is to make Inter one of the top 10 teams in the world," Thohir added.
Thohir bought Major League Soccer outfit DC United in 2012 while oil tycoon Moratti has served as Inter president since 1995.