09 March 2013
Section 234B attracts only if you paid less than 90% of total tax liability as advance tax on or before to 31st March of the concern financial year ending then only 234B attracts on the self assessment tax paid for the period from 1st April to till the month of tax paid.
For example assuming your tax liability is Rs.50000 for A.y 2013-14. So 90% of such tax liability is Rs.45,000 is requiring to pay tax in advance on or before 31-3-2013 to avoid 234B interest.
For your case assuming details provided by you is related to A.Y 2013-14. If you paid total amount at-least 90% of Rs.270000 i.e Rs.243000 upto 31-3-2013 then 234B interest doesn't attracts. You are saying you are paid part amount in February 2013 and remaining paying in March 2013 so 234B interest doesn't attracts on your case.