This work concerns the manufacturing of a composite tube using RTM process. During the preforming stage, a woven braid is laid down and stacked on a mandrel so that reinforcement plies form conical shapes with a defined angle. An innovative experimental preforming procedure has been developed to respect the specific angle. The resin injection step has been studied both experimentally and numerically. The influence of processing parameters such as the injection pressure or the imposed flow rate on the position and the size of possible defects has been evaluated. A numerical study has been conducted to model the flow of resin within the different areas of the complex preform. Planar and through-the-thickness permeability studies were conducted experimentally as a function of the fibre volume fraction and the shear angle. Within the preform and especially along a radius of the part, variation of shear, fiber volume fraction, orientation of yarns and consequently variation of the permeability tensor must be taken into account for the simulation of the resin injection. Simulation results presenting the evolution of the flow front within the preform for different injection cases are discussed and correlated to the experimental study results previously mentioned.