My percentile is 84 is it enough to Qualify in General category

Well your question is not fully clear to me that where do you want to "Qualify", Still I will try my best to answer in a way that satisfies your query.

If you are asking about you being qualified to jee advanced then I would tell you that for this you have to wait until April 2019 because NTA will announce the final result based on the best of two percentile marks and your percentile will differ according to the number of students appearing in the exam.

If you ask about the cut off for getting admission to any iits or nits You must go through article link given below:-

Link-https://www.google.com/amp/s/engineering.careers360.com/articles/jee-main-cutoff

This will give you an idea about how much this year's cut off would be.

Hopefully I have been able to answer your question. Comment below for more queries.