The good thing about carbonatites is that they generally contain a lot of Sr and not so much Rb, so their Sr isotopic signature can be quite resistant against alteration. And for the rest, it depends on what has happened to the carbonatite. Your question is a bit too general to give a real answer...

Thanks Marlina... if both Sr-Nd value of Carbonatite is coming both mantle & crustal   signature &  Pls recommend  any  modelling to show crustal contamination from mantle derived magma???

I am not sure the modeling would solve your problem unequivocally. In the following paper you will at least heave a felling where the trace elements are contained: Bizimis, M., Salters, V. J. M. & Dawson, J. B. (2003). The brevity of carbonatite sources in the mantle: evidence from Hf isotopes. Contributions to Mineralogy and Petrology 145, 281-300.