When I file income taxes, who can see that I filed?

If I file income taxes, who can see that I filed? Does my employer recieve paperwork?
Ok, the situation is this: I get paid cash. My employer doesn’t want employees who work under the table to file income taxes. So, if I file, will he know?
I’ve filed for the last 3 years. Self employed or something like that. The tax professional used Schedule C I believe. Do they see if you filed under Schedule C?
So, if I file and they get audited but I can prove I got the income through DCF paperwork, do they find out I am the one who filed?
There are 7 employees.. 2 are paid by check.

not filed income taxes in India for past 6 years, how to amend it?

I am an Indian citizen, but was studying till I was 21 years old and did not have any income and did not file income tax returns. After 21, I went abroad for study and work and came back when I was 27. So, I did not file any income taxes in India till now. I filed for income tax for this year on my income earned in India. Did I break any Indian tax laws by not filing income taxes for the past years? If so, how can I fix it?
Can someone please advise?

how to avoid capital gain taxes on a land sale?

how many properties can a person invest in from the capital gained from a property sale to avoid capital gain taxes? can one invest in more than one property and buildings or is the tax exemption for one property and a building on that property only? and is there any limit in investing in national bonds or on property or building?