I am facing a problem while molding a transparent PC part, it is like an open box, Transparency is an issue, when I increase the mold temp it sticks onto the core & ejection becomes difficult..any help?

Try with smaller injection speeds maybe? And less switchover pressure but a longer time.

What is mold temp? Try core higher than cav temp...you do not want part to remain in cav. and need it cool to eject.
What is your cycle time?

Did you try mold release? Although it sounds like a temp issue.

What are your overall dimensions on you box ? Are you using conventional Ejector Pins at the top of your core ? Any Ejectors at the base of the Core ? What is your Draft angle on the sides ? Any Texture on the core side walls ? If so, how deep of a texture ? Have you considered a Stripper Plate ejection that pushes the entire Parting Line Surface ? Sometimes with a closed box part you will have a vacuum lock that makes ejection difficult----you may experiment with core side venting if possible. Vented Ejector Pins and possibly using a "Blow-Back" pressure through the vented pins may help as well.

Thanks guys...it is a core insert...we tried to keep core temperature higher than cavity temp...but it didnt work somehow..we are getting some whitish marks on the interior of the part....so overall transparency is affected....I guess it is due to higher mold temperature on the core side..or Is it?? Is there anything I can do with cooling of the part...?? should it cool faster or slower in this case??

Mark..Thanks for your suggestion.....box is about 70 mm deep...with a rectangle of 50 x 70mm....it has 2 bosses on the inner side...initially we tried pin ejection on the bosses, however it didnt work out, currently we are using blade ejection on the flat surface of the box....ejection issues have minimized, however part transparency is affected....what processing temperatures can you suggest?? we are molding the part at 270 degrees with mold temp of 70 degrees on the core side(it is a core insert)..part is having a centre sprue...

Have checked that the gate size is right. PC should be injected with slow speed and therefore you need a big gate. What gating system you have there?
Check also the residence time in barrel/hot runner if any, don't exceed the recommended max time.
What flow index resin you have used? Is there any chance to use easy flow resin, remember that the mechanical strength is lowered if changing to easy flos resin. You could use then lower resin temp and risk to decompose will be lower.
Sticking issues with PC are normal and you need very well polished tool or big draft angles.

Also, There are a number of hardcoat finishes that have extremely thin thicknesses that you may consider for your core to improve ejection.

Need separate temp for core and cav. Since your single temp is 70...raise the cav to 90-100. That will allow the core to cool faster and harden the rim for ejection.
Some one mentioned mold release which is great to get your process going. Be prepared for scrap due to distortion from the spray.
You can also raise the nozzel temp,see the PC req...What is your wall thickness? 60 seconds is a long cycle time.