Singhal is a Bharatiya Janata Party (BJP) legislator from Alwar city constituency, around 150km from Jaipur.
"Girls either walk to school or wait for school buses at various points in Alwar. That is when they face lewd comments from mischievous elements," Singhal said.
He argued that most private schools in the city had skirts as part of the uniform.
"It should be prohibited keeping in view the rise of social crimes against women. The school should have pant-shirts or salwar suits as uniforms for girl students," Singhal said in the letter.
He said the proposed school uniform would save the students from extreme weather conditions too.