Civil Servant (IAS/PCS)

Eye sight
6/6 or 6/9 distant vision for good eye. 6/12 or 6/9 for worst eye.
Near vision J1 for good eye. J2 for worst eye.
The correction by lenses only. High standard for the Colour-blind test. No inherent night blindness. Vision should stereoscopic.
Ear-
good listening & normal ear cavity. 1000 to 4000 frequency hearing impairment should not be more than 30 decibels.
Nasal-
clear and free from any polyps and injury, both nasal passages should be clear.
Speech-
The candidate should not stammer while speaking.
Height
Male 165 cm Male (general) & (SC/ ST/ OBC) 160 cm
Female 150 cm Female (general) & (SC/ ST/ OBC)- 145 cm
Chest
Male Minimum 84 cm. Expansion 5 cm.
Female Min 79 cm expansion 5 cm.

A small but respectable number of candidates from graduates from science stream do take up civil services and crack it regularly. However, their number has not really been great enough to leave an impact on the final tally. But, considering the growing clout of scientific thinking and rising need of technocrats in the bureaucratic setup, it is surely seeing a slow and steady rise.
so I suggest you to go for Humanities have traditionally been termed as the bastion of civil services examination. If we look at data released by the UPSC in their annual reports, we can see that humanities subjects have had a higher success ratio compared to others.