St3 before getting st2

no u cannot file ST-3 for F.Y. 2010-11 and 2012-13

if the gross amount chargeable to tax in the F.Y. 2010-11 and 2011-12 is less than the limit specified then thereis no need to apply for service tax registration and hence no need to file st-3

Thanks for ur reply Akanksha......s the Assessee has Turn over exceeding 10 lakhs in F.y 2010-11 & 2011-12 and hence they want to pay tax and file ST returns accordingly.So my query is can they do so as they got ST registration on 18/02/2013?

They can file the return and along with the return Late filing fees..

yes.. agreed with above.. also penalty is also leviable..