We'll assume that you only want to talk about whole numbers.
The smallest 7-digit number is 1,000,000. The largest one is 9,999,999.
They represent (all of the counting numbers up to 9,999,999) minus (the first 999,999).
That leaves 9,000,000 numbers
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Since the numbers begin with 123, they all contain a 3. As a result, they all "contain 3 or 7". So the remaining 4 digits can be any digits and this gives 104 = 10,000 such numbers.
7
A crore has 7 digits.
180
There are 192.