Hello Archit,
Fellow Indian Geek here. I must say good job on the site, you have managed to make something that is usable. Here is some of my suggestions:<p>1) I think you need to get a fancy logo. current one is too plain according to me.<p>2) You are asking customers some sensitive & yet I do not see "Privacy Policy" which is what stopped me from entering PAN No right at first step1. If its already there, highlight it<p>3) A Strong TOS would indemnify from liability. so, You should add a TOS & make customers agree to it.<p>4) Any Particular reason Pricing is hidden from Homepage?<p>5) In welcome email that you send. add few details like name, userid etc. It makes it more original & less fake.<p>6) I understand you want a "Lean UI" but I think more naked than Lean. so spice it up a bit - add some fancy transitions, better typography(Try webfonts) etc.<p>7) For entering Date,javascript validation message says: "Please enter date of birth in format: 25/10/1984". isn't giving specific format DD/MM/YYY more accurate. Further, Any reason you are not using Date Picker?<p>8) Make Login Button more prominent. so user won't try to register again. Your current homepage encourages to everybody to click on that big orange button which is not something you want your existing users should be doing.<p>9) Taxes aren't something that most people understand. so even after such Intutive UI, people will have questions. so highlight your support methods available(Phone, email etc).<p>10) Last & most important: Don't just be a pretty interface to official Website. You never know when incometaxindiaefiling.gov.in becomes irctc.co.in. That's too risky business model. Try to add more value to service.<p>Hope it helps