This script is quite simple. When you get below 300 mana you will equip Ring Of Healing, and when you are above 301 it will equip Life Ring =)
local MANA_EQUIP_HIGH = 301 -- Mana to equip Life Ring
local MANA_EQUIP_LOW = 300 -- Mana to equip Ring Of Healing
local ring_item = finger()
local player_mana = mp()
if player_mana <= MANA_EQUIP_LOW and (ring_item.id == 0 or ring_item.id ~= 3089) then
moveitems(3098, 'finger', '')
wait(500, 800)
elseif player_mana >= MANA_EQUIP_HIGH and ring_item.id == 3100 then
moveitems(3052, '0', 'finger')
wait(500, 800)
end