Application to sixth form help

hi everyone, at the moment I am able to apply to the sixth forms and colleges I would like to go to. specifically I would like some help about when I should apply to my local sixth form. a couple of my friends have already applied and have said that i only need to tell them my predicted grades. even though i could get in with my current predicted grades on my last report from year 10, i wonder if i should wait until i get my updated predicted grades near christmas time and apply with them. would it give me an advantage of getting in using higher predicted grades or would it make no difference if i use my current predicted grades.
for reference:
current predicted grades: 7,6,7,7,7,5,7,66
entry requirements: maths and english grade 5, grade 6/7 in chosen subjects and another 3 grade 6s