JagerMech JM6-S is a Heavy-class 'Mech in Battletech.
The JagerMech S is a Heavy 'Mech specializing in long range direct fire. While lightly armored for its tonnage, it can direct a withering array of AC/2s and AC/5s at distant targets. Closer enemies are handled by a pair of Medium Lasers.
An excellent long range mech, the JM6-S works best when upgraded to a pure AC/5 loadout, though its flexibility means you can run pretty much any loadout and still come out on top.
The default configuration is infamous for being made of glass, and the game's maps makes it extremely difficult to use the full range of its weapons. Typically, the most desired capability in a rear line support mech is knockdown capability, and LRMs are more effective than autocannons in that regard, even without factoring in indirect fire capabilities.
With the 1.1 update, LL's become more viable, and you can swap out both AC/2's for a pair of LL's and some heat sinks, giving you a primary armament of 2x AC/5 and 2x LL. While it has more heat issues than the 3x AC/5 version mentioned above, it also has a higher alpha.
The S variant has enough tonnage to carry 2 x AC10 and 4 tons of ammunition. This makes it a viable 'mech for head-hunting (i.e. A mech specialized in making called shots to opposing mechs' heads), but it would require Kaliyama AC/10+ or ++ (deals 65 and 70 damage, respectively, which can destroy the head in a single shot), and a Tactics 9+ pilot to be effective.
Another option for short range is to put an AC/20 instead of the autocannons, and have 4 med lasers, giving it a strong 200 damage alpha up close. use the remaining tonnage for heavy front armor and jump jets for mobility, and you got a solid close combat heavy mech, especially early on.
The JagerMech S model is highly specialized at long-range Autocannon fire support. It doesn't have much in the way of protection or closer-range weapons, though, so keep it distant and out of harm's way. Especially since its ballistic hardpoints are located on the arms and thus very vulnerable to being shaved off.
Armour is very poor for its weight class and not much better than, for instance, the 55-ton ShadowHawk.
Still, it might be the first Heavy mech you get your hands on on the single-player campaign, and if you have an LRM-equipped medium mech plus the standard-loadout Jagermech then you are in a great position to get knockdowns.