  In this thesis, models have been developed to study the radiation emission
processes from the knots of AGN jets as well as for blazar jets. A continuous
injection plasma model is developed to study the X-ray emission from the knots
of sources 1136-135, 1150+497, 1354+195 and 3C 371. The knot dynamics is then
studied within the framework of internal shock model. In such a scenario, knots
are formed due to the collision of two successive matter blobs emitted
sporadically from the central engine of AGN. Shocks, generated in such
collisions, accelerate electrons to relativistic energies. These electrons
subsequently emit radiation via synchrotron and/or inverse Compton processes in
the radio-to-X-ray energy range. The study of M87 knots involves a two zone
model where the electrons with a power-law distribution are further
accelerated. The synchrotron emission from these energetic electrons is then
used to explain the observed spectrum.
  The limb-brightening feature observed in the radio maps of the BL Lac object
MKN501 is studied considering shear acceleration of electrons at the boundary
of the jet. This interpretation does not require a large viewing angle of the
jet as demanded by the earlier models and is consistent with the constraints
obtained from very high energy studies. In case of MKN421, the dependence of
temporal behaviour of radiation emission on the particle acceleration mechanism
has been studied within the framework of two zone model.
