In this game it would translate over as:
SM Armor Value: 66.8(3+ Armor Save, 4 out of 6)
SM Health Points: 40(4 Toughness, 4 of 10)

Reaper Armor Value: 66.8
Reaper Health Points: 30

A Bolter should deal 13.6 Base DMG*, with HP DMG modified by comparing Strength and Toughness.
Bolter TTK vs SM: 1.75-sec, 8 Bolts, 0.25-sec Fire Rate
TTK vs Reaper: 1.5-sec, 7 Bolts

*Imperial Guardsman(Human) is S3 so used for 10 Base DMG. Using system that rounds to nearest 1/10th, each point of S must be at least 3.4.
For each point of S above target T +10% DMG
If S is 2x or more than target T +50% DMG
For each point of S below target T -10% DMG
If S is 1/2 or less than target T -50% DMG

Any reason you chose to round 2/3 as 66.8 and not 66.7?

Maybe a "soft" lock-on. If the target sees it coming they should have some limited dodging ability, but an unaware target moving in a straight line would be tracked and nailed

wait a sec , why he carry melee knife and pistol ? can he go melee such as dire avenger exarch or banshee or strike scorpion ?

1/6th = 16.7
16.7 x 4 = 66.8

Shots should travel in a straight line and deal both direct and AoE damage, requiring you to lead a moving target to hit them but not requiring direct hits to deal at least some damage.
The Planetside 2 Vanu Sovereignty's Lasher is a great example of how the weapon could be developed.

All Basic Classes are planned to have at least a Pistol and basic melee weapon like a Combat Knife/Knuckles.

but he is same like havoc , and havoc don't use pistol or knife , unless you excute someone

That's bad mathematics and makes me cry. You have rounded with too few decimal places then compounded the error with multiplication.

Try to use a scientific calculator (or a calculator app with a good scientific function) and run the entire calculation in one go:
1/6 x 100 x 4 = 66.666r, rounded to 66.7.

They either need to drastically increase the projectile speed or add a soft form of lock on to the reaper launcher. It takes roughly three and a half seconds for the first projectile to leave the barrel and connect with the ground or whatever at 150 meters which on maps like Harkus is pretty common and a another 3 seconds for all projectiles to explode. We not only have extremely slow travel time but an extremely long time between explosions. If the gun killed with 1 shot this wouldn't be as much of an issue but it doesn't, it takes upwards of 4 direct hits.

I'd be happy with just the speed increase for the projectile. Leading the target is getting into the realms of aiming when the target is off screen in hopes of hitting them seconds later. A stationary target is just a false hope. (The target sits still, I aim, I fire, 1 seconds goes by everything looks good, 2 second target starts moving, impact, target nowhere near the splash damage either...). Frustrating.

I've had more success with reapers waiting on being charged and blasting the ground a few meters away from me as the attacker runs onto the shot. Not how I see "Death from Afar" that is the motto of the Dark Reaper.

Havoks will have both a Pistol and Knife. Please, when talking about how the game should be when fully completed don't talk about the problems caused by its currently incomplete state.

Rounded to the perfect number of decimal places so that with no error comes no compounding via multiplication.

Try to use 1/6th as the base, not 4/6ths\2/3rds. 1/6 = 16.7 rounded to nearest 1/10th.

Agreed on the first suggestion. Not only should the shots travel more quickly but the RL should also have a greater number of shots before reloading. It should essentially be the Eldar equivalent of the HB, rapidly firing mini-rockets at a slower rate than the HB fires but with higher Strength, Armor Penetration and possible splash damage.

HB TTK vs Dark Reaper should be: 1-sec, 6 Bolts, 0.2-sec FR
Accuracy: 2.9-cm spread at 24-meters
Major Damage Drops: 72 and 144-meters

RL TTK vs Devastator should be: 1.5-sec, 7 Missiles, 0.25-sec FR
Accuracy: 2.2-cm spread at 24-meters
Major Damage Drops: 96 and 192-meters

While the RL has a notable TTK disadvantage, it is more accurate, deals its damage at greater ranges and should not provide as hefty mobility penalties on the DR as the HB does on the Dev.

Dev HB Move Speeds Base / When Firing
Forward: 5-ms / 3 or 4-ms
Strafe: 4.2-ms / 2.5 or 3.4-ms
Back-Pedal: 3.5-ms / 2 or 3-ms
Sprint: 12-ms

Aiming should cause the Dev to brace in place even if not in cover, preventing them from moving and reducing their turn rate but reducing their recoil and zooming in for more accurate shots.

Reaper RL MSs Base / When Firing
Forward: 6-ms / 4.5 or 5-ms
Strafe: 5-ms / 3 or 4-ms
Back-Pedal: 3.5-ms / 2.4 or 3-ms
Sprint: 13.5-ms