Interest Income - DTAA between UK and India

[skray]

Hi
I have a number of foreign currency accounts (NRE and FCNR) in India the interest from which are tax free in India.
I live in UK and pay tax on worldwide income. I include all overseas income into my UK tax return and pay tax at 40% (My income from UK sources already reach the 40% threshold).

I was reading these 2 articles on DTAA between UK and India - it talks about tax "spared" rather than tax actually paid.

https://community.hmrc.gov.uk/customerforums/pt/e2005350-a3d9-ec11-bea1-00155d9c9666
https://royaccountants.co.uk/2021/03/25/worldwide-disclosure-taxation-of-interest-income-from-nre-and-fcnr-deposits-for-uk-residents/#:~:text=Brief%20answer%20is%20Yes.,deposits%20for%20NRO%20see%20link.

Could I receive some help understanding the provisions in DTAA at least in outline.
e.g.
1)Am I entitled to claim 15% tax relied despite not paying any tax in India. (e.g. If my overseas interest income in £10000, currently I pay 40% that is £4000 in UK. Should I actually be paying (40-15)=25% that is 2500 only?
2)"UK India DTAA interest can be taxed maximum @ 15% Article 12 (2). Thus, relief restricted to 15%." - does this mean in any event I pay only 15% tax that is £1500 and not £4000
3)"Tax spared relief is restricted to a period of 10 years from the tax year from which tax exemption is first granted from Indian income tax " - what does this mean. The FCNR accounts were opened longer than 10 years back and these are fixed deposits account probably opened longer than 10 years back typically for 1 - 3 years. They are auto renewed. Does this mean I was entitled to the benefits of these provisions in past years, but no longer?. If I close the FCNR and open new ones with a different back I become entitled again?

Thanks in advance
REgards

[skray]

Found more information here:-
https://www.cronertaxwise.com/community/190923-tax-sparing-relief

Suppose my
1)UK income (employment + interest)=55K
2)Indian Income taxable (NRO) = 15K, Overseas Tax paid 1.5K
3)Indian Income non-taxable in India (NRE, FCNR)=5K

I pay UK Tax on 55+15+5=75K and claim relief of overseas tax paid 1.5K.
Am I entitled on further relief on the basis I have been spared paying tax in India on #3 above i.e. 5K?

Thanks