hi,

see mathematics in 10+2 course is mandatory for b.a hons in economics, however you want tp pursue economics as pass subjects so criteria may be changed. I would suggest you to contact with delhi university exam authority for more clarification. however the eligibility criteria for sociology is you need to have 45% marks in 10+2 course, the marks percentage can be counted as 1 of the language subject and any 3 best academic subject. follow the below link to know more details,

http://du.ac.in/adm2019/CriteriaForUpload2019June17.pdf