To turn 100g of 6% THC ABV into tincture with grain alcohol, you will need the following:

1 liter of high-proof grain alcohol (preferably 190 proof or higher)
A large glass jar with a tight-fitting lid
A cheesecloth or fine mesh strainer
A dropper bottle for storage
A kitchen scale
Here are the steps to make the tincture:

1. Weigh out 100g of the 6% THC ABV and place it in the glass jar.
2. Pour the liter of grain alcohol over the ABV until it is fully submerged.
3. Close the lid tightly and shake the jar vigorously for several minutes to thoroughly mix the alcohol and ABV.
4. Place the jar in a cool, dark place, like a cupboard or pantry, for 1-2 weeks, shaking it daily.
5. After 1-2 weeks, strain the mixture through the cheesecloth or fine mesh strainer to remove the plant material.
6. Transfer the tincture into a dropper bottle for storage.

The formula to determine the concentration of THC in the tincture is as follows:

% THC x 1,000 = mg THC per gram of ABV
mg THC per gram of ABV x number of grams of ABV = total mg of THC

For example, with 100g of 6% THC ABV:

6% x 1,000 = 60mg THC per gram of ABV
60mg THC per gram of ABV x 100g = 6,000mg total THC

To determine the amount of THC per milliliter (ml) of tincture, you need to know how much liquid you have in total. If you used a full liter of grain alcohol, you will have 1,000ml of tincture.

To find out how many ml per mg of THC the tincture will be, divide the total mg of THC by the amount of tincture in milliliters:

6,000mg total THC ÷ 1,000ml tincture = 6mg THC per ml of tincture.

So the final concentration of THC in your tincture will be 6mg THC per ml.