|If the information from your manager is absolutely essential and your request has been ignored multiple times, you need to ramp-up the request process. Try to set a meeting with your manager to walk through every key point you need from him. If he still goes into evasive mode, you should proceed with the project by working with the information you have and using other sources and resources to fill in the gaps where possible.|
However, rather than trying to complete a final version of this report, try to finish a first draft within the next month or so. When you are done, give it to your manager and set a formal meeting to discuss it.
Perhaps you will hit all the high marks and your manager will give you the green light to finalize it. In fact, this may have been his strategy all along. Or, he may have wanted to see how far you can go without his input, and he will use this opportunity to provide you with any needed information. At the same time, he may again ignore you. If that is the case, you should simply turn in this project and then turn to your next one.