I will fill water with / by bucket.
Kindly help me with this question
This question appears to be off-topic. The users who voted to close gave this specific reason:
You can say:
I will fill something with water using a bucket.
Here it might be possible to say:
I will fill the water by bucket
I will fill the water with a bucket
I will fill it by bucket
This only works if your reader already knows what you are trying to fill with water. The last example shows that (in English) you are not filling water. You are using water to fill. You might fill a tank, but in that case:
I will fill the tank by bucket
The alternative interpretation is that you want to just fill the bucket, in which case:
I will fill the bucket with water.