Dear manyalakiran,
1. Segment 1 will return you the visitors who are New and placed an order.
2. Segment 2 should not return you any numbers because you cannot set purchase (Order) event twice in the same order i.e. Order can never be equal to 2.
3. Again, you cannot user Order = 2 here and thus the question will be invalid.
4. You can use Time Range in your segments like This Month, Last Month, Last 3 Months, etc., to make sure that the time periods are taken care.
To create the segment based on 1 order, 1 order and more, 2 orders, 2 orders, and more, you should now use Sequential Segments.
Thank You, Pratheep Arun Raj B (Arun) | NextRow Digital | Terryn Winter Analytics