The 50,000 pound prize is to be announced on Tuesday night and is it to be seen whether the bookmakers' predictions reign or Thyail's 'Narcopolis' succeeds in emerging as the dark horse of the race.
Apart from 'Narcopolis', the other books in running are Self's 'Umbrella', Mantel's 'Bring Up the Bodies', Tan Twan Eng's 'The Garden of Evening Mists', Deborah Levy's 'Swimming Home' and Alison Moore's 'The Lighthouse'.
While Self has been shortlisted for the first time, Mantel is a previous winner. Bookies William Hill said it would be the closest finish ever. Its most recent odds for Mantel are 6/4, making her the narrow favourite over Self at 2/1.
However, another bookie has placed Self as the favourite at 6/4, ahead of Mantel at 9/4.
Salman Rushdie, Arundhati Roy, Kiran Desai and Arvinda Adiga have earlier won the prestigious literary prize and if Thayil manages to pull it off, he would be the fifth Indian to claim it.
Chair of the judges, Sir Peter Stothard, said: "This has been an exhilarating year for fiction. The strongest I would say for more than a decade".
Every Booker winning book since 1996 has grossed more than 1 million pounds. Yan Martel's Life of Pi, which won in 2002, made just under 10 million pounds while Mantel's 'Wolf Hall', which was the winning book three years ago, went on to make 5.4 million in sales.
Last year's winner, Julian Barnes's 'The Sense of an Ending', has sold 300,000 copies so far. The ceremony takes place on Tuesday night at the Guildhall in central London.