The answer to what I presume was your real question - "Could the missile have been stopped before it hit the ground?" - is "No". In detail on the subquestions:
- Likely. The Brahmos missile is loosely based on (more like "inspired by") the Granit missile that does have an onboard datalink for target selection. There's no confirmation that Brahmos has the same, but it's reported to be a very sophisticated missile, so it's probable.
However, the launch platform is unlikely to have the ability to use this datalink. It's possible for a combat aircraft - altitude gives comm range, and aircraft are under the singular authority of their crews, so they may be able to do this in time. It's somewhat possible for a ship, while there is a line of sight.
Ground launchers cannot communicate with missiles once they have been fired. This is, if nothing else, due to the horizon effect. Ground launchers are also less sophisticated in general.
Such communications are encrypted. The encryption keys are generated and exchanged at missile boot-up (in modern documented military encryption protocols). If the missile misfired, it doesn't have a datalink established, so no one is able to communicate with it.
- Very likely yes, most such missiles do have a self-destruct capability.
The first Brahmos entered service in 2005 (in many ways, it was ready in 2002), but it's been an ongoing development and modernization project for at least a decade since. Specifically the flight control system and software were modernized and refined in India.
Another Indian missile, tested in 2013, was self-destructed, indicating that India does like this feature in their missiles. Self-destruct is a software feature, so, even if the original missile didn't have it, India had the opportunity to add it in the modernization process.
As with retargeting, communicating with the missile may not be possible, especially from the ground. Again, it would only be possible with a properly initiated launch, not a misfire. Self-destruct implies an encrypted link - you don't want the enemy to be able to just turn your missile off.
- No. Not realistically.
It's possible if you expect the missile to potentially veer off course, and are actively monitoring for that event, and are trained and pre-authorized to take that action.
This high readiness happens when you're test-firing a missile.
For a missile that has been accidentally fired on the ground during maintenance, as reported, the answer is a resounding no.
First, the maintenance crew has no authority over the missile and its target selection or self-destruct (if present). They also don't have enough time to figure out what's going on, who has the authority, how to contact them directly, what exactly to communicate, and so on. It's going to go up and down the chain of command.
Second, the fire control module isn't in the TEL (transporter-erector-launcher) truck. The land-based Brahmos missile uses a separate command post vehicle.
If the missile truly misfired, rather than was fired by mistake, that means the issue most likely occurred within the missile or the TEL. The command post in this case most likely wouldn't even be online.
Third, a misfired missile might not have all of its own computers properly started and set up. If it's just the engine that started, there's nothing to control the missile. Since Brahmos is supersonic, it must've had a working flight control system, but many other systems could still be offline or improperly initialized.
P.S. Related: How can a supersonic cruise missile be intercepted?
Anti-ship missiles are built to deal with attempts to shoot them down. So the design principle is "fail-deadly". If radar and comms are destroyed, the missile will try to hit its last target point. A misfire without proper target input is likely to be treated the same way as combat damage.