6 is completely fine in Eng Lit
And it’s Eng Lang that matters more!
Universities ask specifically for maths and Eng Lsng grades
U don’t not need higher it Lit dwww
If you specifically wanted to apply to Oxford for something then it could be worth considering resitting to boost your overall GCSE grade profile, since that is something they will consider - but they don't care about that individual subject. However for some degree subjects (e.g. maths) GCSEs are less important at Oxford, and for most if not all, good performance in the relevant pre-interview assessment (e.g. PAT, MAT, TSA, etc) usually can ameliorate poorer GCSEs.
Although resitting it might encourage you to appreciate the importance of paragraphing