Watch the nine-minute speech captured by a fan on video. Warning: some offensive language in background.
Brown urged new owner Charles Green to sell the club to the supporters and announced he plans to lead a fans' buyout of the Sevco group.
The former defender, who declined to transfer his contract as a scout over to the newco, received supportive cheers and applause from a large crowd who had gathered to participate in the hour-long protest.
Their demonstration came ahead of an unconfirmed report that the Scottish Premier League and Scottish Football League have drawn up a detailed package of proposals to solve the Rangers/newco impasse, including the club being relegated to Division 1 and being replaced by Dundee.
However, fans of many Division 1 clubs are already putting pressure on their chairman to follow the lead of SPL counterparts and deny the Ibrox side access to anything but Division 3.
The SFL said in a statement: "The Scottish Football League, for the last number of days, has been involved in intensive discussions with the Scottish Premier League, the Scottish Football Association and other crucial stakeholders in our game, to try and address, in a positive way, the current critical issues affecting our game.
"The SFL will today send a briefing document to its member clubs – a logical and positive communication which will hopefully eliminate some of the understandable doubt, threats and insecurities that are apparent within the game at the moment.
"The consultation document will fully explain the short and long-term benefits of a number of scenarios which we will be considering at a full club meeting next week.
"The SFL is trying to address the question of whether we are in a position to accommodate a solution to the Rangers FC scenario. We are trying to achieve a solution which will be in the best interests of the SFL and the wider game.
"The Scottish Football League can confirm that no agreement has been reached between the SFL and any other body regarding the position of Rangers Newco in the First Division."
Green's consortium completed the purchase of the business and assets of Rangers for £5.5million earlier this month after the club was consigned to liquidation.
However, fans have accused him of not being up front about who his investors are and have asked for more clarity about his consortium and plans for the future of the club.
The protest was organised by supporters' group the Union Bears, which said: "We demand answers from Mr Green immediately. The situation is critical and we as fans must act now."
Banners were tied to railings across the road from Ibrox which said: "Rangers fans demand answers" and "Murray, Whyte, Green. Same face different name", while there were also effigies of Craig Whyte and Green.
Brown had earlier told Sky Sports News: "The Rangers fans worldwide are behind this (selling the club to supporters). They want to buy our club so that every fan worldwide owns their own club. Every fan will be given one vote.
"If they invest, we will set up a bank account and all the season ticket money can go in there. Gone are the days of the money that we spent; it is going to be handled differently this time.
"The fans are going to buy it over, we have the backing of some powerful people who are going to invest, and the fans will invest. If Charles Green says he's got the title deeds in his name, we will make an offer. We are going to get our club back but we need a bit of honesty from Charles Green."
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