Interest for section 234B and 234C added while filing ITR

I’m working as a software engineer in an IT company.
I’m filing ITR form-1 for FY 2019-20.

My company had deducted and submitted TDS of around Rs 7000 on 6/01/2020 to IT department.
Initially, while filing the ITR, my tax payable was coming as Rs 0.

After adding interest from saving account, my taxable salary became more than 5 lakh.

Now, it’s showing tax payable according to the slab(Rs 12500 + 20% of amount above 5 lakh).

This is fine.

However, it’s also adding a total of around Rs 4000 interest against below sections:

• Interest u/s 234B
• Interest u/s 234C

As per my understanding, salaried professionals shouldn’t be considered for advance tax.
Is my understanding correct?

If yes, then why the section 234 interest amount is added?

If no, then what is the process and how could I have avoided it? We get our form 16 from company sometime in July then how can we calculate and submit advance tax on time?

Any responses are appreciated!

Thanks
Rahul