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The important break is at under 9's, Under 8's play Walla rugby, no tackling, have some fun, run, pass etc. He wouldn't notice any difference between himself and an under 6 at this level. Under 9's play Mini rugby which is tackle, uncontested set-piece, pretty much under 8's with tackling.
If transport is an issue, all junior rugby generally takes place at one of three nominated venues until U/11s
Your local club might be one of the ones which has a long drive every saturday to play, and it might work out better to pick a different club....I don't know if that ever happens, but it's somethign you might want to keep in mind.
Southern zone (generally) plays at Thomas oval in Kwinana, Central at Britannia in Leederville and northern (I have no clue, never been there)
from 11's up all games are at Britannia.
That's all I know, apart from if he's keen, whilst there's no tackling, get him involved, he won't get hurt by bigger kids and he can play a couple of years in 6's before going up anyway (He'll be 6 this year anyway right)