I want to know that what should be the exact length of a website title according to google? Harm of length over maximum length allowed?
There is no exact length other than what you can see in the search index. However dependent on place it is generally 64 to 69 characters (including spaces) for visual display effect. You can go over this and of course write much shorter to. You really should not try and stick too rigidly to trying to get the 64 to 69 character display limits.
Thanks mate. I want to confirm one more thing that if I use 100-110 letters in title will it be effective?
For getting found for those included keywords perhaps but not effective for the visual pull in the search index, if you get my drift... Edit However the visual pull can still work with the cut off point being the reason for clicking as the lead in sentence/words compel of course