climb, scale
攀 centers on using hands to move upward or over something: climbing a steep surface or scaling a height.
攀 combines 樊 (a phonetic component suggesting grasping or entwining) with 手 (hand) to express climbing by hand. The exact historical development of 樊 is uncertain, but the character consistently relates to using hands to pull oneself up.
The top part 樊 looks like a tangled thicket or lattice, and the bottom 手 is a hand. Picture a hand reaching into a tangled vine-covered cliff to pull the body upward: climbing and scaling by hand.
For ハン, imagine a hand (手) climbing a steep cliff, and with each pull you let out a breathy 'han!' sound: han -> ハン.