I have iron level of 17 ug/dl and iron binding saturation of 4%. is it too low to go for iron infusion? can i take oral iron supplements which would increase these numbers (slowly)? i am an active person with healthy diet (mostly vegetarian)?

You have significant iron deficiency by those numbers. IV iron is NOT absolutely indicated unless you could not tolerate oral iron or ongoing blood loss is still present and you need a quick way to replete your iron storage with on going iron loss in case of moderate & severe anemia. There are plenty of means for repleting iron orally by meds and high iron contained foods so IV iron is unnecessary

If you can tolerate oral iron, take it, also take multivitamins. Check you iron level in 3-6 months, if it has improved, continue with the oral medication.