you can check the opening and closing rank for jee main 2015 and 2016 from the link given below:

https://josaa.nic.in/webinfocms/Handler/FileHandler.ashx?i=File&ii=62&iii=Y

http://josaa.nic.in/Result2016/result/OpeningClosingRank.aspx

If Odisha is your home state a rank around 7500 will ensure you to get into the best branch there i.e Mechanical. For other state student you need around 6000. For other branches the count extends till 40000 for GE category students.

Please check the link provided to get a better information:-

https://engineering.careers360.com › Home › Articles

All the very best and good luck.