From January 2018 we are using new Content of Tally. for Downloading use following Link.
and for Marathi Content wait till March End.
About Old Student of Dec:
It's migration process are finished you can check it now but follow below Task
1)Sent to learner Klick Beta Era from Solar
2)Check Health From LF Check Content
3)Go to Report Select Course Select Batch Generate Report and see your all learner are present in report
For Tally Old learner Old Course (50) New learner New Course (225)