Let me clear you, IAS is not a degree it is just a job, a Government job. IAS, Indian Administrative Service is a type of job which you can get after Clearing UPSC cse. Cadre will depend upon your rank or sometimes the vacancy of that particular place which you will apply.

Coming to the degree then you can take up any degrre as it you need just a Under grad. degree as a Pre requisite.

Just join any colleges nearby your home. I would suggest you to go for BA in Political Science or History or Geography.