As you all know that now IRA is conducted at first day of ilp. So, may be, it would be difficult to start preparing after reaching here. Since, lot of time consumed in document processing and other formalities. You will also experience fatigue during the day. So it is better to prepare beforehand.
IRA would be conducted after lunch break at 2:00 PM probably. The group is divided into 50 members and it is based on your serial numbers, you will be allotted to different groups. They will be provide you a temporary id number in the starting.
And, now you required 55+ marks to passed the exam. Question will be based on your aspire. So, read it thoroughly. And don't take it light otherwise you will be rescheduled in next batch. Result of IRA 1 will be shown to you just after completion of test except Chennai ILP. If, you didn't score more than 55 then they will also give you second chance but it will be only for those who have marks more than 52.5.
IRA 1 for those would be conducted on the same day or the next day depending on the situation.
Now, talking about IRA 2, it is just for selecting students who knows more than others (those are called DIFFERENTIAL). The advantage of being differential is that your training would complete 15 days before from your batch. They say that IRA 2 is based on Tech Lounge but it is not true. All questions will be out of course. Most of peoples do not clear that but it has no effect on your joining. Since, you will be going through normal training (Which is better than Differential). Numbers of differential students may vary according to the batch. Mostly it is 30-40 students.