East Sussex County Council handle transfers from Infant to Junior School at age 7+. You apply for a school place online.
There is a set of priorities that decide who gets a place. These include looked after children, siblings and how close you live to the school:
For full details see the how school places are offered in the East Sussex schools guide.
Changing schools during the school year
To apply for a place at West Rise junior school in the middle of the school year, ask the school for a paper form or apply during the school year online.
You have the right to appeal against a decision on school allocation.
See Considering making a school appeal? for helpful advice, information and deadlines.