Sadonaros

After completing the elite four, getting the national pokedex with 85 pokemon owned i still cant access the cave to retrieve the ruby from the rocket team in order to proceed with the ceruluean cave. What am i missing? thanks for any help !

thank you again kind Sir !

@Sethsen thank you for your reply, is there also an ability or skill that increases the chance of the pokemon having the item? also is there a link that i can check the chances of the pokemon actually having it? i dont seem to get any info from the npc to relearn skills on how many mushrooms he actually needs.

How can i get mushroom from paras? i tried thief on the Mt.moon cave paras but i get nothing , i only kill it. ty !