Hi,
There is no standard/readymade format available for campus drive proposal.
Address it to concerned college Principal - start with salutation - give a brief about your company including nature of business, number of locations etc. Then brief about your requirement with expected qualification, percentage of mark required, your salary details for the freshers etc. Conclude the letter asking the college to confirm on students availability for campus interview on a mutually convenient date.
Please note that you may get numerous samples through online or some of CITEHR member may share a template but I strongly recommend you to draft a letter by your own so as to improve your communication skills. In case if you are not confidant of your letter then you may post it here for correction.