i think It is the process of one month for which we get registration from Commissioner of Service Tax where you are assessee.Procedure as follows
1.Amend your registration online-i.e Amendment ST-1, it can be go through www.aces.gov.in
2.then you take print outs of amended certificate&confirmation letter.
3.You submit it to your s.t dept where is along with, xerox copy of pan,proof of earlier registration, proof of address and other copies as mentioned in confirmation cert.That is successfully amended.Then submit wiht copies to the Superintendent of S.Tax Dept.
Otherwise you will be levied penalty
thank you