IBall Nirantar UPS is value for money product if you are using a desktop with normal power supply.(usually Upto 450w local power supply which are working with 55-60% effiecency) It will give good back up.
I used this power supply in past and it served well.
when it was new, it provide 25 min backup but as time pass the backup reduce and after 2 and a half year the backup reduce to 7-10min.
but I purchsed it at 1150rs so its a decent performer power supply at low cost. Battery of ups can be change if circuit board is working ok. This Ups turn on even there is a little fluctation in electricity so that all equipments connected to it, will never face any damage because of electricity problem.