hi the main problem is when i try to use the rigid body simulation the ropes separate from the jewel i want to know if i can activate the rigid body and not separate it from the main model
You could do it this way:
Create 3 objects: the 2 ropes object (2 meshes within 1 object) / the cube (your character) / a plane.
Subdivide the plane, give it a Cloth simulation, assign its 2 last vertices to a vertex group that will be the cloth Pin Group, increase the Speed Multiplier value of the simulation if you want the animation to go faster:
Give a Surface Deform modifier to your rope object, with the plane as Target, click on the Bind button:
Select the cube, shift select the rope, switch to Edit mode, select 3 vertices, make the vertices parent with CtrlP:
Play the animation and you'll get that: