Here are the details of how all the satellites will be placed in the orbit.
The satellites will be separated from the launch vehicle in different directions. The separation angle and time of separation will be such that one satellite will not collide with another.
The satellite separated from the launch vehicle will have a relative velocity of one metre per second. So after 1,000 seconds the distance between a satellite and the rocket will be 1,000 metres.
The satellite that gets launched first will move at a relatively faster velocity than the next satellite that is launched. Due to different relative velocities, the distance between the satellites will increase continuously but the orbit will be the same.
When the vehicle reaches the orbital condition, there will be a pause for sometime till the disturbances die down which will be followed by the preparation for separation.
At an orbital altitude of around 500 km, it would take the vehicle 90 minutes to complete one orbit. So there is sufficient time to launch all the 103 satellites.
ISRO’s workhorse PSLV-C37 rocket carrying no less than 103 satellites will be launched in the first week of February. 100 out of the 103 satellites are foreign, while only 3 are Indian.