Always use the spelling ” One Lakh” only on cheques, It is the correct one. We have to follow the spelling of One Lakh as per RBI guidelines. RBI uses One Lakh spelling whenever they need to mention 1,00,000 in their circulars and even on their website also. So don’t’ get confused in between One Lakh and One Lac, whenever you are going to write a cheque for One Lakh then write as One Lakh only.
Here is an example of how RBI mentioned One Lakh on their website:
One Lakh Rupees Only Cheque Image
Similarly whenever you are going to write a cheque for 2 lakhs then write it as 2 Lakh Rupees Only.
For 5,00,000 Rs write it as Five Lakh Rupees Only.
For 10,00,000 Rs write it as Ten Lakh Rupees Only.
In general, you can use any spelling, but when you are writing a cheque or any financial related document then write as Lakh.
Write it as Two Lakh Fifty Thousand Rupees Only.