HELLO SHADAB
Well you are weak in mathematics but i suggest you to make that subject strong since most of the engineering parts is dependent on mathematics.
now coming to your problem just try those entrance exams where there is no negative marking so that your chances might increase such exams are Like
COMEDK, SRM, VITEEE( applications are out)etc.
ILl be mentioning some links where you get the infomation about the a bove exams
1.VITEEE https://engineering.careers360.com/exams/viteee
2.SRM https://www.careers360.com/university/srm-institute-of-science-and-technology-chennai
3.COMEDK https://engineering.careers360.com/articles/comedk-uget
HOPE IT HELPS!!