Offer Conditions for Royal Holloway

Does a foundation year for Computer science in royal Holloway require a Practical endorsement pass for science? Offer did not state that it requires it so not sure.

I see no mention of such a requirement on the web page for BSc Computer Science (with Integrated Foundation Year) or in the Admissions Requirements section of their Undergraduate Regulations. So I would assume not.

u 100% sure? If I do not pass phyiscs practical and they reject my offer even if my grades have been met can I appeal decision?

I'm 100% sure that there is no such requirement mentioned on the web page for BSc Computer Science (with Integrated Foundation Year) or in the Admissions Requirements section of their Undergraduate Regulations.
However, it might be worth contacting their admissions team to make absolutely sure.

Unrelated but if I have been given conditional offer of ACC but manage to get A*BD, at time of results day, does the ucas system automatically reject the offer as I did not meet it or is there some sort of consideration (before clearing) for example if the physics paper was extremely difficult like last years.

About a week before results day, your firm and insurance choices get your grades. If you meet the offer conditions then they're obliged to confirm your place. If not, then they have the option to confirm your place as a "near miss" candidate. UCAS are not involved in this process.

What is a “near miss candidate” and does that mean I will know if my firm accepted me a week before results day?

A "near miss" candidate is one who missed their offer conditions, but came close (near) to achieving them. A candidate who was asked for ACC but who achieved A*BD has missed their offer, because the D is below the required C. However, universities can opt to confirm the place of such candidates anyway. In order to do this, they need to have places left on the course (once they've confirmed the places of candidates who've met their offer conditions).
You won't get to find out what's happened until results day. At the same time that exam boards send your grades to UCAS, who send them to your firm and insurance choice, public access to UCAS is disabled. This happens a week before results day.
This gives the universities time to update UCAS with the details of those candidates that the uni will accept. For candidates who've met their offer conditions this will obviously be straight-forward. However, if a university has (for example) 10 places left on the course having done that, but has 20 "near miss" candidates, they need some time to go through those candidates to decide which they want. Hence why they're given a week to make those decisions and to update UCAS.
Then, on results day, public access to UCAS is re-enabled and you get to find out what decision was made.

Does a foundation year for Computer science in royal Holloway require a Practical endorsement pass for science? Offer did not state that it requires it so not sure.

For a near miss candidate, will their place have been confirmed in results day as the uni will already know how many places they have left etc or does it mean that I would have to call the uni to enquire at time of results day?