Prototype STL File Creation

I already have a full set of detailed design files for my prototype and now need a clean, watertight STL that can go straight into a slicer for 3-D printing and visualization. Every dimension, tolerance,... (Budget: ₹600 - ₹1500 INR, Jobs: 3D CAD, 3D Design, 3D Modelling, 3D Printing, AutoCAD, CAD/CAM, Fusion 360, Solidworks)