Is experience as a Lecturer in Europe/UK considered relevant in Indian inst. (IIT/IIIT/NIT) for Assistant Professor positions in CS?
In the UK, a Lecturer position is approximately equivalent to an Assistant Professor position in the US, with the exception that in the UK it is usually a permanent position, while an assistant professor in the US needs to get a tenure before becoming a permanent faculty. (On the other hand, the UK system doesn't have tenure at all.) 

The 2nd paragraph of the OP is unclear.