Lakh simply means that there must be 6 digits in the number.

Count the number of digits

A number with 10 lakhs place must have 7 digit in it.

Think of a place value chart

The number has 6 digits which means it will start with lakh.

Count the number of digits

The number has 7 digits which means it will start with ten lakh.

Put the number in the place value chart

Lakh simply means that there must be 6 digits in the number.