Hello Nandha,
In your case you can use a reverse proxy to fix the URL (like Apache, IIS and even the Firewall). It is also possible to use the Web Dispatcher to rewrite the URL when it arrives to the Web Dispatcher and before sending it to the AS, please take a look to the following URL:
Rewriting URLs - SAP Web Dispatcher - SAP Library
I think in your case the RegRewriteUrl sentence will be something like this:
RegRewriteUrl ^/index.html. /sap/bc/sap/index.html
The only thing I don't remember is if it shows always to the user the same URL or if it changes. There is a nice guide about how to configure the Web Dispatcher with SSL through the whole landscape:
Best regards.