It is reported that Supreme Court in BSNL vs Man Singh case has ruled that the daily wagers ( casual / contract labours ) even if working for many years are not entitled to be regularised. The decision of the labour court and the High Court to the contrary has been cancelled by the Supreme Court.
We are trying to get a copy of the judgement to find out the exact judgement.
VAN Namboodiri's Blog 
The judgement was isued on 14/10/2011 against civil appeal 8748/2011. You can refer to website of supreme court and search judgement with respondent name man singh. It says a daily wage labour worked for more than 240 days in a year claim permenent post in bsnl. Some cost i.e., 200000 is payable to daily wage employee.
Thank you for the information.