Hi Faisal Maulana Ibrahim, I'm sorry, but I think that your question cannot be answered unless you provide a few more details, e.g. what type of ligand.

Faisal Maulana Ibrahim

I agree with Frank T. Edelmann

but in general, you can use chimera for ligand preparation.

Thank you for your response Dr Frank T. Edelmann and Dr Anas Alobaidi

I attach a picture of the molecule that I will be docked

my specific question, 1. How is the preparation of the ligand especially in forming the coordination bond between the radioactive metal (Tc-99m) and its organic compound, what application should I use? Can you use ChemDraw or Gaussian? 2. Can I dock the compound using AutoDock4? Thank you very much