Interest from a loan given to a family person is taxable ?

Yes, income tax is payable on the interest income mentioned by you.

Your initial basic doubt was cleared.

It will fall under the category of Income from other Sources.

There is no separate rate of tax for the interest income. The same will get merged in the total income,  and then will get taxed according to the tax slab applicable to you. 

Please approach a Chartered Accountatn for better clarification and to handle your Income Tax Return filing.

If you are considering income for the year 2017-18, take into account amount receivable as salary. Add to that income receivable as interest. Compute tax at the rate applicable for the year. Deduct from the amount tax paid by your enployer as TDS. The remainder will be the additional tax payable by you. You should have paid 30% of this remainder as advance tax before 15-09-2017 and another 30% before 15-12-2017. As you have not presumably paid the advance  tax so far you will also have to pay interest on the unpaid tax at 1% SI per month.

You make a rough calculation and pay the amount now.  You have to file returns for this year on or before 31-07-2018. Well before that date you go to the website of the Income-Tax Department and register yourself with your PAN as your user name and a password which you choose yourself. You can also download income-tax return form for efiling in XL form. The form will be self-explanatory and you can fill it up yourself. You will have to show the amount you receive as interest under 'Income from Other Sources."  You will get Form 16 from your employer and you will have to enter particulars from that also in the return form. After you have completed the form go to the tax computation section and fill up taxes paid. Complete also the verification section including date. Then click on the button 'Calculate Tax'. Tax will be automatically calculated. If the tax paid by you is less than what is payable including interest, it will appear as 'tax payable'. Pay that tax enter it in the form and convert entire return into XML format. You can upload the XML format after logging in with your usename and password. You can working in a software firm. All these things should easy for you. Don't worry about contacting a Chartered Accountant and all that. You are not a Shah Rukh Khan.