Which stream is better to choose in 11th standard if I want to become an IPS officer?

You can choose any stream in 11standard to Become an IPS Officer in future.. for IPS officer exam you just pass graduation with any steam ..
You have to choose stream according to your own interest and abilities

Here I am giving you information about required eligibility for Indian police service examination organized by union public service commission ..

Eligibility :
You have to passed a graduate degree in any discipline of any well recognized of the Universities

Age limit :
You must be at least 21 years of age at the time of filling the Civil Services (Preliminary) Exam form
Maximum age : Not more than 30 years of age..

Physical requirement
Height – Male 165 cm & ST (not the SC/ OBC) – 160 cm
Female 150 cm & ST (not SC/ OBC)- 145 cm
Chest – Male Minimum 84 cm. Expansion 5 cm.
Female Min 79 cm expansion 5 cm.

Vision Requirement for IPS
Parameters Better eye (corrected vision) Worse eye
Distant vision 6/6 or 6/9 6/12 or 6/9
Near vision J1 J2
Corrections permitted spectacles
Color vision requirements High grade