Has the application dates for UPSC IAS 2025 been extended?

No, the Commission do not mention any Minimum Qualifying Marks for the General Studies Paper 1. But there is a criteria of Minimum 33 % for the General Studies Paper 2 (Aptitude) paper. 

The IAS Prelims exam is conducted offline in the pen and paper mode. There is no sectional cutoff in the IAS prelims exam because the number of questions from a section is not fixed and they vary year to year.

The Union Public Service Commission conduct the Civil Service (IAS) main (written) exam offline in pen and paper mode. This exam is a descriptive type exam where the candidates are required to breach this cutoff score to get a call for the interview phase.

The IAS prelims cutoff means the minimum marks required to clear the prelims exam in the category of the candidate. The Union Public Service Commission conduct the IAS prelims exam to filter the candidates and limit the numbers for the main (written) exam. The Commission conduct the prelims in offline mode. 

No, the number of IAS vacancies is fixed to 180. Every year, the Commission recommend 180 candidates for the Indian Administrative Services (IAS). In case of any change, the Commission will notify.