These are basically fee for technical services. If the services are actually taxable in India meaning they are either used in any project physically present in india then they are taxable in India by virtue of section 9 of Income tax act. Incase they’re not taxable by virtue of section 9 you can use form 15CA part D to remit the payment to UK without any tax withholding.
But if the services are taxable in India then they’ll suffer tax withholding. The rate can be either a lower 10% or 20% incase you don’t have PAN.
Now as far as form 10F is concerned you can only file that once you obtain PAN number in India. And in case you do as per section 115 of Income Tax Act you can have a lower tax deduction of 10% on fee for technical services and will also have no need to file Indian Tax Return by virtue of sub section 5 incase there is no other income apart from the withholding one.
Nothing can be done if you have no tax liability in your country.
Feel free to reach out to discuss further.