Dear team,
If i would like to provide a force against gravity to the whole body such as lifting a body, where i should provide. I have changed the Gravity in the AnyStudy folder. Such as

AnyBodyStudy Study =
AnyFolder& Model = .Model;
tStart = 0;
tEnd = 1;
nStep = 61;
Gravity = {0, -9.81, 0}*0.1;

I dont see it right. Kindly provide me a solution for the below statement.

I want to lift whole body providing something like 40% weightlessness to the body.Simulating a weight harnessing system!

that depends on where the harness will be attached to the human.
following line will reduce gravity to 10% applied to everything in the simulation/to every segment in the model:
Gravity = {0, -9.81, 0}*0.1;

if that is not the case, you need to apply a load to those segments that will be carried by the harness.
If you know the force that is in the harness you can do that witha with a AnyForce3D.