I think you should submit it in the begining of the year because they need to deduct TDS every time the interest is due so it will be better if you deposit it in the start.
Point number 16 you have to mention the total amount of interest that you are going to earn from bank.
Point number 17 means your total income including this bank interest and point number 19 means you need to mention that it is interest from bank TDS section under which it's TDS is deducted and the amount.
No submitting form 15G will ensure everything but even then at the end of the year do check your form 26AS to check if someone deducted your TDS.
Your interest income should be below 250000.
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