As you have asked about the important dates for the application of Joint Admission Test for M.Sc. (JAM) conducted by Indian Institute of technology (IIT), I am giving you information about it, check below for the details
I want to tell you that the process for JAM for this year has been completed but I am giving you information just for your reference about the dates,

All important dates
JAM 2016 Event Date

Commencement of Online Registration and Application on JAM 2016 website 02 Sep 2015

Last Date for Payment of Application Fee through e-Challan 10 Oct 2015

Last Date for Online Application Submission and Uploading of Documents on
the Website 14 Oct 2015

Last Date for Change of examination City/Town maybe permitted, if request
with a valid reason for the same is received in the office of the Chairman,
JAM 2016, IIT Madras along with a Demand Draft of Rs. 500/- drawn in
favour of Chairman JAM-2016, IIT Madras 31 Oct 2015

Download of Admit Card from JAM 2016 website 31 Dec 2015

Date of JAM 2016 Examination 07 Feb 2016

Announcement of the Results of JAM 2016 23 Mar 2016

Submission of Application Form for Admission on the JAM 2016 Website
15 Apr 2016

Last Date for receipt of request for change of category in proper
format/rectification of defective documents at IIT Madras

10 May 2016

Declaration of First Admission List 03 Jun 2016

Declaration of Second Admission List 20 Jun 2016

Declaration of Third and Final Admission List and the Closure of Admissions
through JAM 2016 04 Jul 2016