please correct this sentence if there is any mistake.

He told him that rain is not yet abated.If it comes down I will come to your house.

He told him that the rain has not yet abated: "If the rain comes down hard, I will come to your house."

If you don't want to include a quotation, then you'll need to convert the pronouns in the second sentence to correspond with those in the first sentence.

if the rain comes down hard means lessening of rain?. please tell me madam

No, when rain comes down hard, it's REALLY raining! Flooding can often occur then.

If it comes down lightly, then it's a nice, soft, gentle rain.

He told him, "The rain has not yet abated. If it comes down, I will come to your house."

Correction:
1. Added quotation marks before and after the direct speech to indicate that the speaker is saying those words.
2. Changed "is" to "has" to match the verb tense of "abated," which is past tense.
3. Capitalized the first letter of the sentence after the quotation marks.
4. Added a comma after "him" to separate the direct speech from the rest of the sentence.