India and countries such as Saudi Arabia and the United Arab Emirates have sought access to monitor the services as they fear heavy encryption makes BlackBerry convenient for terrorists to use without being monitored.
"There are certain categories (monitoring of communication) where things are possible, there are certain categories where the same kind of interception is not possible," Telecommunications Secretary R.
Chandrashekhar said late Friday.
India's government is testing various ways to intercept BlackBerry communications.
It earlier said BlackBerry maker Research in Motion (RIM) had offered solutions to access the BlackBerry messenger, Internet, voice calls and short messaging services.
New Delhi had initially threatened to ban BlackBerry's corporate email service if the firm failed to come up with ways to monitor it by the end of August. Now it has said it will review the situation near the end of October.
India has also said that RIM will have to set up a server