Contractual employee in principal employers pay roll

Sir, I am working in sanskrith collage as a library assistant on contract basis under Rashtriya sanskrith sansthan deemed university New Delhi(under MHRD). I joined there on [deleted] on daily wage basis. and worked upto 9- 9-2013 with a break of 2 days in every 89 days.From 13-9-2013 to till date working as contractual basis with consolidated salary of 9000 with a break of 2 days in every 89 days.2 LDC and 2 peons also working there like this.all are directly appointed by Principal employer not through a contractor.all are working in the post of a retirement post.still the post are vacantI.I would like to know the following things. 1. We are getting 1 casual leave in each month.no other leave.are we eligible for all kind of leave which applicable for permanent staff?including maternity and paternity leave. 2.Are we eligible for gratuity? 3. Are we eligible under recent verdict of supreme court equal pay for equal work? 4.can we approach court for regularizing the job ? Regards, Lijeesh.R Kozhikode