Assuming you are an Indian student, you should start planning your study abroad procedure at least one year in advance. This will give you enough time to research your options, figure out the costs involved, and ensure you have all the necessary paperwork.
If you leave everything until the last minute, you may find yourself rushed and stressed out, which is not an excellent way to start your studies. Plus, it is always better to have more time to make an important decision rather than rushing it.