How many BIPs do you need to run the masternode and receive rewards for maintaining the network?

In Minter, there is no predetermined amount of coins that allows you to join the network as a masternode. You must be on the list of validating nodes (masternodes). Their number starts at 16, and every 518,400 blocks (~ a month) places for another 4 are added, until the total number reaches 256. The selection is made according to the size of the stake (own + delegated funds). More detailed information is available in the documentation — https://docs.minter.network/#section/Validators