#!/bin/bash
s='INFO 56783 Count [5987]
INFO 67988 Count [4986]
INFO 27679 Count [9865]'
awk -F'[][]' '/Count \[[0-9]+]/ && $2 > 5000' <<< "$s"
IyEvYmluL2Jhc2gKcz0nSU5GTyA1Njc4MyBDb3VudCBbNTk4N10gCklORk8gNjc5ODggQ291bnQgWzQ5ODZdIApJTkZPIDI3Njc5IENvdW50IFs5ODY1XScKYXdrIC1GJ1tdW10nICcvQ291bnQgXFtbMC05XStdLyAmJiAkMiA+IDUwMDAnIDw8PCAiJHMi