Rules for reference;
SR5 p. 66 Resources
The exchange rate is 2,000 nuyen per Karma, or 5,000 with the In Debt quality.
SR6 p. 66 Step Four: Spend Customization Karma
Remember that you can spend Karma to buy cash for the next step at a rate of 2,000 nuyen per point of Karma, or 5,000 with the In Debt quality.
SR6 p. 77 In Debt
When you spend Karma for cash, every point of Karma you spend gets you 5,000 instead of 2,000 nuyen. Each point of Karma spent also puts you 5,000 nuyen into debt with someone very dangerous and capable of collecting. You must repay interest at a rate of 200 nuyen per level of this quality, which addresses interest only, not principal...The quality can be bought off purely with money; if the principal is repaid the quality is eliminated. This quality can be obtained only during character creation, not during gameplay.
Without In Debt you have the option to get 2k per karma and it will not give you a debt and and you don't have to pay interest rate.
With In Debt you have the option to get 5k per karma but this will also give you a debt of 5k per karma and you have to pay interest rate.