While John Abraham is taking tuition classes, the matter on the black board keeps changing between camera shots.
In the movie, John Abraham introduces the ISA (Indian Space Agency) scientist as someone who has refused offers to work for international space agencies, like NASA. This is not possible, since NASA being a US government agency, allows only US citizens to work there. There is no way that the US government will hire a foreigner, to work in a facility that requires a security clearance.
Logo of Bhabha Atomic Research Centre, which is shown in the movie, was not available in 1998.
John Abraham is wearing Bata Power shoes which were not available back then in 1998.