Yes, there is a provision for rechecking or challenging the marks after the IIT JAM Mathematics Exam results are declared. Candidates who are not satisfied with their marks can apply for a revaluation or request for a challenge. The process for rechecking or challenging the marks is as follows:

Revaluation Process:
1. Candidates who wish to apply for revaluation of their answer scripts need to submit an application form along with the prescribed fee to the organizing institute within the specified time frame.
2. The application form can be downloaded from the official website of IIT JAM or obtained from the organizing institute.
3. The fee for revaluation is non-refundable and may vary from year to year. Candidates should check the official notification for the current fee details.
4. The revaluation process involves rechecking of the entire answer script by examiners to ensure that all the answers have been evaluated correctly and marks have been awarded accurately.
5. The revaluation result will be communicated to the candidate by the organizing institute. If any change is made to the original marks, the updated marks will be considered for final result calculation.

Challenging the Marks:
1. Candidates can also challenge the marks awarded to them in the IIT JAM Mathematics Exam.
2. To challenge the marks, candidates need to submit an application form along with the prescribed fee and supporting documents within the specified time frame.
3. The application form for challenging the marks can be obtained from the official website or the organizing institute.
4. The fee for challenging the marks is non-refundable and may vary from year to year. Candidates should refer to the official notification for the current fee details.
5. Along with the application form, candidates need to provide valid and substantial reasons for challenging the marks. They should also submit supporting documents, if any, to substantiate their claim.
6. The organizing institute will review the challenge and supporting documents submitted by the candidate and take a decision accordingly.
7. The decision of the organizing institute regarding the marks challenged will be final and binding.

It is important for candidates to note that the revaluation or challenging the marks does not guarantee a change in the final result. The decision of the organizing institute is final and cannot be challenged further. Therefore, candidates should carefully consider their options before applying for revaluation or challenging the marks.