Clarification related to Section 234b of IT Act

Sir, if there is any tax payable after claiming TDS credit, than on that interest u/s 234 B is leviable.

As you mentioned, there is FD interest is being added, So, it's due to that your overall income increase and subsequently tax liability increase..

So, interest is payable on that increased tax liability ( because it's not already Paid).

In this case how would I know what would be my interest income when FD rates are fluctuating so frequently ? And in this kind of a scenario what should an individual do to avoid such fines? 

To avoid such interest you have to estimate (not exact) your total income and tax payable thereon.

If your tax payable after TDS amount is more than 10,000 than you have to pay advance tax.

or otherwise you can declare your estimated interest income to employer (if you want) than Employer will deduct you TDS accordingly.

Sir, in my opinion Interest under section 234B is applicable when:
Your tax liability after reducing TDS for the financial year is more than Rs 10,000 and you did not pay any advance tax.
OR
You paid advance tax, but advance tax paid is less than 90% of ‘assessed tax’.
In any one of the above cases, interest under section 234B shall be applicable. Interest is calculated @ 1% on Assessed Tax less Advance Tax. Part of a month is rounded off to a full month. The amount on which interest is calculated is also rounded off in such a way that any fraction of a hundred is ignored.