You should select yes to declare foreign income and yes to claim foreign tax credit relief on capital gains.
You need to declare the capital gain in the capital gains section and then also in the foreign section of fill in your return.
As you are claiming relief for capital gains payments, the relief can be up to 100% of the foreign tax paid.
If you are being asked to choose a percentage rate, you are in the wrong part of the tax return.
On page 2 of 2 of foreign income details, you should tick yes to "Capital gains - foreign tax credit relief and Special Withholding Tax".
This will bring up the section on capital gains for property.
You should then tick the box for "Residential property and carried interest", to answer the questions on property disposal.