To a certain extend any country could profit from investing in bitcoins, as long as the long term price trend is positive. The problem of course for a country in bankruptcy is that they don't have any money to buy bitcoins in the first place. They could try and print more of their fiat money and buy bitcoins, but nobody would be selling his bitcoins for the inflated fiat money. The bankruptcy comes from not meeting financial obligations that have been given in the past. Somehow Sri Lanka needs to work on restructuring their debt first and try to get their budget in order. Otherwise it will be hard to get foreign investors to help and rebuild the country. Switching to bitcoins as a form of payment could be helpful as well for Sri Lanka. As long as all the people have access to bitcoins it could be a good alternative for the people, but the government will probably not agree. Once switching to bitcoins as a legal tender the government has no influence over the money supply and can't print new money freely.