Pilot apprised Modi about the floods in Jalore, Pali, Sirohi and Barmer districts.
He accused the state government for not being able to help the people hit by the deluge and the slow paced rescue and relief measures and sought Centre's assistance.
He claimed that 12 persons have died so far in the flood-hit areas and the state government has not given any compensation to the aggrieved families.
Pilot in his letter urged the prime minister to announce a relief package for Rajasthan Rs 500 crore similar to what has been to given to flood-hit Gujarat.
"I have got to know about 536 bovines death in Pathmera gaushalas and several others are on death bed. The BJP government talks a lot about cow protection but the talks are far from reality. The state government should take immediate steps to save bovines," Pilot said in the letter.