Difference between c11 and n11c in self assessment challan 280

IF NO PENALTY UNDER 271-1-C WHILE FILLING E CALLAHAN, USE OF N11C OPENED THE GATE OF COMPLETING THE DEPOSITION OF SELF ASSESSMENT TAX IN SBI NET BANK ING SITE. IS IT CORRECT OR DID MISTAKE IF MISTAKE PLEASE WHAT SHOULD HAVE BEEN DONE AND NOW WHAT COULD BE DONE TO MAKE IT GOOD.