Hi Mamadou Issa,
The contingency reserve is controlled by the Project Manager and is part of the budget for the project. The contingency is cover known risks.
the management reserve is held by the management committee and is used for unknown risks. It is not included in the budget for the project. It is held by the management committee and the project manager has to apply to the committee for the funds to be allocated to the project.
Hope that helps.
Sarah