ServerList101
TheNRK: 1.7 - 1.16, Minecraft PE server
bedrock.thenrk.net
FallenTech PE, Minecraft PE server
fallentech.tk
214 / 215
MythicStar, Minecraft PE server
mythicstar.tk
16 / 50
EmperialsPE, Minecraft PE server
play.emperials.net
59 / 100
Cuboss Bedrock Edition, Minecraft PE server
pe.cuboss.net
Elytra Network, Minecraft PE server
bedrock.playelytra.com
TaleCraft, Minecraft PE server
play.talecraft.life
Fictional Craft Associations, Minecraft PE server
play.fcape.vn
6 / 1000
UltimateNetwork, Minecraft PE server
play.utlimatenetwork.eu:25565
Deep_Coder, Minecraft PE server
deep.mcnetwork.me:41476

Minecraft PE Prison servers

On MCPE Prison servers you usually start in Mine A and then you have to mine resources and rank up to advance and get access to higher level Mines.

MC PE Prison as RolePlay?

Along with classic Minecraft PE Prison some servers also offer RolePlay system, with cells and ranks players can choose from, you can be prisoner or prison guard.