I have wrongly uploaded the signature in place of photograph .Am i be able to correct this?
Different examinations have different deadlines to correct mistakes in application. Please mention the name of the exam you have applied for.
If it is for jee mains then you can not correct it now as the correction dates are over on 22nd January 2018.
IF this is for other entrance exams then you have to check out their application form correction dates on their respective websites.
You can contact the exam authorities also for details.
Good luck.