  We construct samples of jetted active galactic nuclei (AGNs) with
low-frequency radio data from the recent released TGSS AD1 catalog at 150 MHz.
With these samples, we compare the properties of jet power for blazars,
radio-loud narrow-line Seyfert 1 galaxies (RL-NLS1s), young radio sources
(YRSs) and radio galaxies. The jet-disk connection, and the unification of
jetted AGNs are explored. On the Eddington ratio --- Eddington-scaled jet power
plane, jetted AGNs can be generally divided into two populations. Low power
radio galaxies, low excitation FR IIs (LEG/FR IIs), and most YRSs show larger
jet power than accretion power, while FSRQs, RL-NLS1s, and high excitation FR
IIs (HEG/FR IIs) are on the contrary. LEG/FR IIs share similar jet power
properties with HEG/FR IIs, while their accretion properties are different with
the latter. These facts suggest an evolutional sequence from HEG/FR IIs, LEG/FR
IIs to FR Is, where the accretion and jet activities get dimmed gradually.
LEG/FR IIs are the transitional objects that accretion processes have switched
off, while jets are still active. After correcting the contribution from radio
core of blazars, the unification between blazars and radio galaxies is
confirmed with the jet power distributions. The unification involved RL-NLS1s
is more complicated than the simple scenarios of black hole growth or
orientation effect. In addition, our results manifest that low synchrotron
peaked BL Lacs (LBLs) contain two distinct groups on the distribution of jet
power, with one group similar with FSRQs and the other similar with
intermediate synchrotron peaked BL Lacs. The LBLs with higher jet powers might
be the aligned counterparts of LEG/FR IIs.
