CA report is a report given charted accountant (CA). This report gives us detailed information about your property Net worth:This includes value of your home, land
agriculture, industries, cars and any other commodities.
Find some local charted accountant in your area and tell your case. That's it.
It helps Vo to understand that you have strong ties (Assets) in your country and helps you to exempt from one of possible rejections.
I hope this helps.
Though i am not an expert i would strongly recommend to add your father Tax reports or income certificates (If it is high income),If you apply under general category and keep less documents if your academic profile is good. don't make Vo to smell something fishy.
What do u mean by any firm,, what kind of firm do this,, this the work of architect engineer and he must do it ,,, if there is any firm ask them if they have a registered engineer if they have then its fine,,
Generally, there are land valuation firms. You can easily find one for your city through google. You pay them the fee and they evaluate your property and provide you a certificate.