Hi hpshah,
Although the interest from a public provident fund is not taxable in India, it is taxable in the UK, where the beneficial owner of the interest is resident in the UK.
This interest is declared in SA106, where the sum is over £2000.00.
The exemption to small amounts of foreign income advises "all your overseas employment income and interest is subject to foreign tax".
As your PPF interst is not subject to tax, this rule cannot be applied and the interest declared on the tax return, either in SA106 or if the remittance basis is used, the unremitted interest, should be declared in SA109.
Have a look at section 9 of
Guidance note for residence, domicile and the remittance basis: RDR1
Thank you.