whether you use the word "inquiry" or"investigation" in teh name of your firm does not amek any difference!
You ahve as much poers to investigate or inquire as a lawyer as any ordinary citizen has. But because you are a lawyer so public will coem to you with their cases hoping that you must be knowing teh Law related to your chosen field of activity.
Te difference between a Lawyer investigaating a case and an ordinary person doing so is that a Lawyer has the legal bent of mind an the knowledge of teh relevaant laws so he will collect such information only which is useful for teh case. An ordinary person would mostly go by his individual frrlings and emotions and not by law
You must note that there is no restriction on a lawyer or any one investigating a case or a matter in his Private Capacity. But teh facts gathered cannot form a part of any official document unless legally acknowledged by soem due process of law.
I will give u an example
There are public spirited Lawyers who file PILs
Now before they fiel PILs tehy have to do a lot of investigation and research and enquiry. But the information that they gather cannot be accepted as an Official document. But when they fiel a PIL on teh basis of that information and that information is vetted by Courts and is used in Judgements it becomes a part of teh official records