Hello Shiv, I would like to tell you that cutoff of JEE mains does depend onlast year's cutoff and there is no fixed criteria or there is no trend that this year cutoff will be this because last year and last to last year it was this, then NO, you are wrong.

Cutoff mainly depends upon the number of students passing the exam and will be eligible for JEE advanced exam. As it is fixed that these many studemst must appear for advance exam so according to them cutoff changes every year. So no one can estimees the correct cutoff, don't believe on fake news, and as it is seen reult will be out till 31 january. 

Good luck!!

Hope it helps