l have a Bolero-sportz (2003 model). It has leaf type suspension at the rear (l think all other models of bolero have the same). Is it possible to change or use coil spring type sustention instead of using leaf type. For example tata siera, safari and new Scorpio have spring type. Please help me to solve this..........

Yes it is possible to change the leaf spring to Coil Spring type. Lot of modifications will be required. If u notice, The leaf Spring connects the Axle with the vehicle. A coil spring cannot do it . You wil have to get a Tie bar made or use from Tata Safari etc. Then also u will have tomake moutings on the axle & body ( Under carriage of the car) . All this requires a very competent workshop . Also the mountings for the shock absorber might hav eto be changed.

And then Saftey is an Issue when doing such modifications.