Hi Suresh Patel,
Capital Gains Tax arises from the disposal of assets, such as property or shares.
Whereas, interest from savings accounts attract Income Tax.
If you are resident in the UK and use the arising basis, you would need to declare the gross interest and tax deducted, in pounds sterling, in the foreign section of an online Self Assessment tax return or the supplementary page SA106, when submitting the SA100 tax return. To avoid double taxation, you can claim a Foreign Tax Credit Relief against the foreign tax paid. You can see more information here:
Self Assessment: Foreign (SA106)
Thank you.