[archonus]

clan can get reputation points only in 2 ways :
1) members of clans level up
2) war other clan and kill members of other clan
requerimient: clan must be level 3 or more

1.3. CLAN REPUTATION
1.3.1. Only clans of 3 level or more can acquire clan reputation points when clan members get new level of their

player level up range reputation points reward

20-25------ 2 rep points
26-30------ 4 rep points
31-35 ------6 rep points
36-40------ 8 rep points
41-45 -----10 rep points
46-50 -----12 rep points
51-55 -----14 rep points
56-60 -----16 rep points
61-65 -----18 rep points
66-70 -----21 rep points
71-75 -----25 rep points

on war :
if you kill a player of other clan in war , your clan gets 1 reputation point
if a player of your clan gets killed in war, your clann loss 1 reputation point

source : http://ftp.inn.eu/forum/l2/Amarantha/cl15/L2CEUpn.pdf