It refers to air combat manoeuvring mode of the radar, where the radar creates several sweeping patterns so that a radar lock is generated instantly and automatically. It's used for navigation. It helps you join your formation or identify other formations once you have taken off. ACM mode is used to find your trail position in your group.
18NM is the safest range scale for trail, normally it's done at much lower ranges, so it denotes the radar can use it at such a large scale even though it's so small.
150Km should be the instrumented range. It means the radar won't bother about targets it picks up beyond that range regardless of the type of target and displays only targets within 150Km from itself to the pilot. It's a pretty impressive range for such a small radar. Most larger MS radars are instrumented to 150 to 300Km, so it most definitely is impressive. It likely provides Mig-21's Kopyo-M level detection range which is enough for the Jaguar to use the ASRAAM to its max range against air targets. At low altitudes that's deadly since AAMs do not have greater range than 20 or 25Km.