Extension of articleship

You have to send Form 108 anyway as it is regarding completion of articleship. 
Further, since you have taken excess leave of 31 days and served it under the same employer, you were required to send Form 107 alongwith Form 108 within 60 days of the expiry of the normal term of articles. 
In your case, since 60 days have elapsed, you need to submit Form 103 instead of 107 for the excess period that you have served.