Form 15G is submitted by any individual below the age of 60 years.
Form 16 is provided by employers to their employees which includes a detailed breakdown of the salary structure.
You have to deduct the TDS if your landlord is an NRI (non-resident Indian).
Before deducting the TDS, your employer asks you to provide tax saving proofs in order to adjust the TDS.
The earlier you file your returns, the quicker your returns have a chance to be verified.