Hii

If you apply to the colleges which do not require the entrance exam score then yes you can get college based on board score and 75% is not a bad score. But generally all the colleges require entrance score. JEE is the common entrance for all colleges but some states have their own entrances like MHCET and some universities also conduted their own tests like IPUCET for IP university and SRMJEE for SRM university.
So you need to be sure that which ever college you apply to require only board marks and not entrance but it is suggested that you do opt for entrance exams so that you chances of admission incrrease

Thanks!