What can be done if an aspirant has made a mistake in choosing the optional/exam centre/language etc. while filling the UPSC form?

A candidate should avoid submitting more than one online application and that is why the examination form should be filled with utmost caution and attention.

If the candidate, after submitting the form has realised that he/she has made a mistake in choosing the optional subject/exam centre/language etc then a fresh application form with all correct details can be filled again. You can even change your optional subject,examination centre or any other incorrect details in the new form. After making amendments in the new form,submit it online before the last date of the examination in the same way as you had previously did and make the payment again.The data provided in the last application (highest RID Number), that is successfully submitted online, is accepted by the Commission. All previous applications are ignored as these are amalgamated with the last completed & finally submitted application.