Tata Steel and Brazil’s CSN today entered the auction ring for the prized trophy — Anglo Dutch steelmaker Corus Group — amid reports the bid could go as high as 11 billion dollars.The nine-round auction called by the UK Takeover Panel to decide the winner between the two suitors began at 10 pm IST.Tata Steel had bid $9.2 billion against CSN’s much higher $9.6 billion last month, prompting the UK Takeover Panel to intervene and pick the winner through open bidding. Ahead of the auction, Tata Steel’s board met today to discuss strategy for the auction, besides approving earnings for the October-December quarter, during which it had submitted its preliminary bid for Corus. Tata Sons Director Arun Gandhi, along with investment bankers and advisors, is camping in London.