1. A computer-implemented method for serving one or more advertisements during streaming of dynamic, adaptive and non-sequentially assembled video, the method comprising: receiving at an advertisement serving system with a processor, a set of preference data associated with a user from a pre-defined selection criteria and a set of user authentication data, wherein the pre-defined selection criteria corresponds to a digitally processed repository of videos; fetching at the advertisement serving system with the processor, one or more tagged videos related to the set of preference data of the user from the digitally processed repository of videos, wherein the one or more tagged videos being fetched based on a correlation of a set of tags associated with each video of the one or more tagged videos with the set of preference data associated with the user; fragmenting at the advertisement serving system with the processor, each tagged video of the one or more tagged videos into one or more tagged fragments, wherein each tagged video being fragmented into the one or more tagged fragments, wherein each tagged fragment being characterized by a pre-determined interval of time and wherein each tagged video being fragmented based on segmentation of the tagged video for each pre-determined interval of time; segregating at the advertisement serving system with the processor, one or more mapped fragments of the one or more tagged fragments into one or more logical sets of mapped fragments, wherein the one or more mapped fragments being segregated based on a positive mapping of keywords from the set of preference data with the set of tags associated with each tagged fragment of the one or more tagged fragments; mining at the advertisement serving system with the processor, semantic context information from each mapped fragment of the one or more mapped fragments and each logical set of mapped fragments of the one or more logical sets of mapped fragments, wherein the semantic context information comprises an object specific context information and scene specific context information of each mapped fragment and each logical set of mapped fragments; and clustering at the advertisement serving system with the processor, the one or more logical sets of mapped fragments into corresponding one or more logical clusters of mapped fragments; allocating at the advertisement serving system with the processor, one or more advertisement slots; inserting at the advertisement serving system with the processor, at least one type of the one or more advertisements in each allocated advertisement slot of the one or more advertisement slots, wherein the one or more advertisements being inserted based on the mining of the semantic context information, an analysis of the set of preference data and a dynamic set of conditions and wherein the one or more advertisements being inserted in the one or more advertisement slots in a real time; and assembling at the advertisement serving system with the processor, at least one of the one or more logical clusters of mapped fragments and each of the one or more advertisements present in each advertisement slot in a pre-defined order of preference to obtain an assembled video, wherein each logical cluster of mapped fragments being assembled based on the analysis of the set of preference data and the semantic context information.