Sentiment analysis is a powerful data mining technique used to determine user’s opinion regarding an organization, event, person or product. Micro blogging sites & other social media platforms are gaining massive popularity now days & millions of people comment positively or negatively about various events person in their comments or parts. Micro blogging sites facilitate the public to share & review their opinion & file events in their posts. Sentiment analysis or opinion mining on micro blogging data mining feat. The proposed system is designed to perform sentiment analysis on micro blogging sites using machine learning techniques with variable weighted grading to various definitive words to be positive, negative or neutral. The positive or negativity of words in a tweet is scaled on a factor of 1 to 5. Assigning weight to determined sentiments allow more natural/fuzzy jurisdiction than a simple binary system. Also, a neuro fuzzy inference system is used to compute a grade for specific search keywords which may be on event/entity etc. Thus their presented tool becomes indispensable for anyone who is interested in public sentiment on a event/entity such as NGO’s, social frame works, marketing agencies, manufactures, art industries such as film industries, political parties etc, whoever is affected by public opinion.