It is 1 GB total and not per day. I am also receiving sms for this. Only sms is 100 sms/day. (UNLIMITED Local, STD and Roaming calls+1GB 3G/4G data and 100 SMS/day for 28 days. Non-commercial use.)
Rs.149 offer sms only states 1 GB/day apart from unlimited calls and 100 sms/day. (28GB(1GB/day on all handsets) along with UNLIMITED Local+STD+Roaming calls & 100SMS/day,28days.For Non Commercial use)